Anatomic Sciences Nuggets

ANATOMIC SCIENCES REVIEW FACIAL VEINS LYMPH USC messed up the following questions: 1979 Q79 (all of these structures pass through the diaphragm) 1989 - The one about which is not a branch of Celiac or its branches. It says Left gastroepiploic, answer is inferior pancreaticoduodenal. Questions I just didn’t include: 1982 Q92 -

CELLS Components of cells o Plasma MB:  Dynamic, selectively permeable MB enclosing the cytoplasm  Between cell wall & cytoplasm  Composition: • Lipids (phospholipids, cholesterol, glycolipids) o Cholesterol increases mechanical stability; also decreases MB fluidity, but prevents freezing o Increasing unsaturated FAs increases fluidity • Proteins (integral MB proteins & peripheral MB proteins) o All transport proteins are integral MB proteins • One layer of charged lipids on either side of a layer of neutral lipids  Cell coat and microfilaments are attached to the cell membrane (golgi complex is not) o Cell Wall:  Protects the cell from changes in osmotic pressure  Anchors flagellae  Maintains shape o Fluid stuff:  Protoplasm: • Viscous, translucent, watery material that is a primary component of animal cells • Contains large % water & inorganic ions (K+, Ca2+, Mg2+, Na+) & naturally occurring organic compounds (e.g., proteins) o Irritability  Property of protoplasm responsible for cell being sensitive to a stimulus  Nucleoplasm: • Protoplasm of the cell nucleus – plays part in reproduction • Communicates with the cytoplasm by way of nuclear pores o Molecules < 40kD can diffuse freely between nucleoplasm & cytoplasm thru the pores  Cytoplasm: • Protoplasm of the cell body that surrounds the nucleus, converts raw material into energy • Site of most synthesis activities • Contains cytosol (viscous, semitransparent fluid that is 70-90% water), organelles, and inclusions (metaplasm)  Metaplasm: • Name given to lifeless material stored in cytoplasm • EX: glycogen (an example of a cytoplasmic inclusion), fat deposits, pigment granules—including lipofuscin (yellowishbrown substance that ↑ in quantity as cells age), and melanin (abundant in epidermis of skin & retina) o Lipofuscin is the “wear & tear” pigment o Microtubules:  Specialized type of filament composed of polymerized tubulin (protein)  Cylindrical hollow structures in the cytoplasm of all eukaryotic cells  Provide support and assist in cellular locomotion  Flagella and cilia o Flagella:  Present in humans – only in the spermatozoa  Core composed of microtubules • 9 double circumferential microtubules and 2 single centrally located microtubules  Much longer than cilia  Move w/ an undulating snake-like motion o Cilia:  Short, hair-like projection from the cell MB  Beat in coordinated waves

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Core composed of microtubules • 9 double circumferential microtubules and 2 single centrally located microtubules • 9 + 2 arrangement of microtubules o Similarities between Flagella and Cilia:  Nine sets of doublets, two singlets in center  Basal body • Essential to function of cilia and flagella • From the basal body, fibers project into the cytoplasm, possibly to anchor the basal body to the cell  Move by contraction of tubular proteins o Axoneme:  Characteristic 9+2 pattern  Peripheral pairs share common wall of 2-3 protofilaments  Central pair of tubules are separated from one another and are enclosed w/in a central (single) sheath. Doublets and central sheath linked by nexins o CenTRIoles:  Nine sets of triplets  The microtubule organizing center of the cell o Centrosomes:  Contain centrioles Microfilaments:  Much smaller than microtubules and have contactile and structure groups • Contractile is made up of o Double-stranded helices of polymerized actin o Actin and myosin • Structural is made up of o Tonofilaments – support the cell and provide attachments for Desmosomes, which anchor contigous cells, and terminal webs , which anchor microvilli  What layer are they found in????  are they used in hemidesmosomes at the basal layer = stratum germ/basale, I’m going with Spinosum? • They are found in ALL layers except for corneum  This test Sucks!  Involved in local movement, by sliding filament movement (as in muscle fiber microfilaments) o Microvilli:  Think Microvillaments  Core of microfilaments  Intestines  Primary purpose is to increase functional surface area (not flagella or cilia) o ***Hey: Microvilli have microfilaments; Cilia have microtubules – don’t screw it up!!! o Stereocilia:  Long, nonmotile microvilli that cover the free surface of some of the pseudostratified columnar epithelium which line the inside of the Epididymis  S for Sex and Stereocilia  Different from Cilia in that they are Nonmobile and have microvilli (microvillaments) NOT microtubules  Facilitate the passage of nutrients from the epithelium to the sperm by increasing the epitheliums surface area  Also present in the ductus (vas) deferens, which is also lined with pseudostratified epithelium Intermediate filaments:  Rope-like filaments that function in structural roles Barr body:  Sex chromatin body  Genetic activity of both X chromosines is essential only during the first weeks after conception • Later development only requires one functional X • Inactivated X chromosome appearing in dense chromatin mass attached to nuclear MB of normal female  Absent in normal males • If a male has a barr body, then he has Klinefelter’s (XXY)  Sex of embryo determined if Barr body presence as early as eight weeks  Important in recognition in epi cells because it tells us sex Cytoskeletal elements:  Form network of protein structures Nucleus  DNA is found principally in the nucleus  Feulgen Reaction – test to distinguish beween DNA and RNA  Tells us what the Nucleus is FEUL full of Nucleolus:

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Site of rRNA synthesis (not DNA, tRNA, or mRNA) • NOTE: rRNA is the most abundant RNA in the cell  NOT bound by a membrane (unlike nucleus, lysosome, mitochondrion, & pinocytotic vesicle) Ribosomes:  Site of protein synthesis  All protein synthesis begins on free polysomes Smooth ER (ribosomes are absent):  Steroid synthesis (vs. Protein Synthesis for RER) • The Q reads: Smooth ER predominates in steroid producing cells, but not in protein producing cells  Protein synthesis for use inside the cell  Intracellular transport  Detoxification reactions (hydroxylation & conjugation)  Glycogen degradation & gluconeogenesis (glucose-6-phosphatase is an integral MB protein of the SER)  Lipolysis begins in the SER  Production of bile salts (when in hepatocytes)  ***Hepatocytes & steroid hormone producing cells of adrenal cortex are rich in SER Rough ER (ribosomes are attached):  Protein synthesis for use outside the cell – aka, site of synthesis of secretory proteins  Also site of N-linked oligosaccharide addition to many proteins  Think Osteoblasts  Associated with RNA – repeated again & again & again on tests (rRNA)  *Cytoplasmic RNA is localized in granular endoplasmic reticulum  Has regions that are smooth in appearance – called transitional elements  ***Mucus-secreting goblet cells & Ab-secreting plasma cells are rich in RER  Active cells – characterized by an abundance of rough ER (fibroblasts, osteoblasts) Golgi apparatus:  Flat, membranous sacs or cisternae arranged in stacks (the stacks are called dicytosomes) w/ two poles • The cis face receives material • The trans face is for transportation function  Packages, stores, modifies & sorts products – post-translational  Packages secretory material and forms lysosomes  Forms glycoproteins for extracellular use  Proteoglycan assembly from proteoglycan core proteins  Modifies N-oligosaccharides on asparagine  Adds O-oligosaccharides to serine & threonine residues (O-linked glycosylation)  Procollagen filaments formed here from polymerization of amino acids!!!!! • Polymerization of molecules into collagen fibrils occurs in the Golgi Lysosomes:  Cytoplasmic MB-bound vesicles containing glycoprotein hydrolytic enzymes that digest & destroy exogenous material  Lysosomes deal w/ biochemical breakdown & phagocytosis in the oral region  Are formed in the Golgi apparatus (they bleb off of it)  Are called to action when the cell produces too much proteins Peroxisomes:  Contain oxidases, enzymes capable of reducing oxygen to hydrogen peroxide and hydrogen peroxide to water  Bile acid synthesis occurs in peroxisomes Vacuoles:  Store & excrete various substances w/in the cytoplasm Glycosomes – store sugar (found in liver) Mitochondria:  Threadlike structures w/in the cytoplasm that provide ATP  Similar to bacteria in shape & size  Reproduce by dividing (also like bacteria)  The most important organelle or component of a cell for oxidative processes = mitochondrion  Contain a double MB (inner & outer MBs) • Outer MB: o Smooth, continuous, permeable o Contains a lot of porin (integral MB protein that forms channels in the outer MB) • Inner MB: o Impermeable to small ions (due to high content of cardiolipin) o Enzymes for ETC & Oxidative Phos are embedded in the inner MB  Both mitochondria and nucleus have double-unit membrane (not lysosome, Golgi complex, or rough ER)  Maternal DNA Link

• Contains cyclic DNA Crista of the Mitochondria • Stores and provides more surface area for chemical reactions to occur (Protein NZs) Embryonically early cell types/forms: o Mesenchymal cells (mesoblastic cells)  Potential to proliferate & differentiate into diverse types of cells  Form a loosely woven tissue called mesenchyme or embryonic CT o Mesectoderm (ectomesenchyme)  Derived from ectoderm, especially from the neural crest in the very young embryo  The primary source of cranial connective tissue cells is the ectomesenchyme o Neural crest cells:  Give rise to spinal ganglia (dorsal root ganglia) and the ganglia of the ANS  Give rise to neurolemma cells (Schwann cells), cells of the meninges that cover the brain and spinal cord, pigment cells (Melanocytes), chromaffin cells of adrenal medulla and several skeletal and muscular components of head o Fetus Blood Cells  Developing fetus blood cells are found in the red bone marrow, liver, spleen, and lymph nodes Important Cells—Function or Location o Macrophage—phagocytosis, defense against bacterial infection  Activated by gamma-IFN  Can function as APC  Kupffer cell—liver  Splenocyte—spleen  Histiocyte—loose CT o Mast Cells—mediators of inflammation on contact w/ antigen, same as Basophil in that it secretes Heparin & Histamine  Mediates allergic reaction – involved in type I hypersensitivity reactions o Schwann—form myelin sheath around axons of PNS  Derived from neural crest cells o Sertoli—produce testicular fluid (not testosterone) o Leydig—produce testosterone o Fibroblast—produces collagen and reticular fibers, most common cell of CT o Osteoblast—forms bone matrix and gives rise to osteocytes o Sustentacular (supporting) cell—internal ear (organ of Corti), taste buds, olfactory epithelium. They are the taller cells on the basement epithelium. o Pyramidal—cerebral cortex (cerebrum)  The pyramids contain upper motor neuron fibers only o Endothelial—lining blood and lymph vessels, endocardium inner layer o Ependymal—lining brain ventricles and spinal cord o Ganglionic—in the ganglion of peripheral to CNS o Globular—transitional epithelium (kidney, ureter, bladder) o Prickle—stratum spinosum of epidermis o Chromaffin—adrenal medulla and paraganglia of Symp NS o Purkinje—cerebellar cortex (cerebellum) o Clara—terminal bronchioles o Goblet cells—mucous MBs of female reproductive tract, respiratory tract, and intestines o Interstitial—CT of ovary and testis o Islet—pancreas o Juxtaglomerular—renal corpuscle of kidney o Hepatocyte—liver Cell replication: o Chromosomes:  = DNA + protein (histones)  Appear as chromatin granules called chromatids, attached to centromeres when replicating o Chromatin:  A complex of DNA & proteins (the proteins are either histone proteins or non-histone proteins) • Histone proteins: o (+) charged proteins enriched w/ lysine & arginine o Involved in DNA packaging • Non-histone proteins: o Enzymes invovled in nuclear functions such as replication, transcription, & DNA repair  Is the cell component that is genetically continuous from one generation to the next (not nuclear membrane or golgi complex) o Euchromatin: (Eu means Good and Loose!!) – Truly transcribed. 

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 Loose form of DNA & transcriptionally active Heterochromatin:  Highly condensed & transcriptionally inactive  Almost the entire inactive X chromosome somatic cells in a woman is in this form Mitosis:  Splitting of nucleus & cytoplasm→two diploid (daughter) cells w/ identical genetic constitutions • Keeps the same 2N (diploid) – the Q reads: The diploid number of chromosomes is perpetuated in somatic cells by a process of mitosis  M phase – mitosis (karyokinesis) division of the nuclear parts of cell (no protein synthesis) • See Below (PMAT)  Cytokinesis – division of the cytoplasm, accompanies mitosis  Interphase (inactive phase) – period between one mitosis and the next o G1 phase – 1st growth phase  By far the most variable cycle period timewise among different types of cells o S phase – when DNA is replicated o G2 phase – 2nd growth phase  Four active phases: • Prophase o Gradual coiling up of chromatin in nucleus o Individualization of chromosomes, initiation of mitotic spindle w/ centriolar duplication o Phosphorylation of the nuclear lamina during prophase initiates nuclear disassembly • Metaphase o Disappearance of the nuclear envelope & nucleoli o Chromosomes line up at the equatorial plate o Spindle is complete • Anaphase o The chromosomes split longitudinally and migrate to poles o Beginning of cell division • Telophase o Nucleolar restitution w/ nuclear envelope formation o End of cell division o # of chromosomes after telophase???  46?? Only if you’re counting PAIRS BEFORE Cytokinesis • Cytokinesis o Splitting of the cytoplasm o Occurs right after telophase o NOT essential for Mitosis to occur Meiosis:  Gametes – genetic material between homologus chromosomes is intermixed  Two divisions separated by a resting phase  Total of 4 daughter cells, each w/ ½ the original # of chromosomes  Goes to Haploid CONNECTIVE TISSUE

Types Epithelial tissue CT Proper Muscle Nervous tissue

Description & Function May be one or several layers thick; lower surface bound to a supportive basement MB of glycoprotein, mitotically active tissue; line all body surfaces, cavities, and lumina and are adapted Highly vascular (except cartilage); contain considerable intercellular matrix; mitotically active tissue, support or bind other tissues and provide metabolic needs Limited mitotic activity; fibers are adapted to contract in response to stimuli; movement of materials through the body, the movement of one part of the body Limited mitotic activity; respond to impulses to and from all body organs

CONNECTIVE TISSUE - CT in general: o Derived from mesenchyme (mesoderm) o Contains more intercellular material than cells o Most common cells are the fibroblasts & macrophages - CT Types:

Example Outer layer of skin, linings of GI tract, urinary bladder, ducts and vessels; alveoli of lungs; and covering of viscera and body Tendons and ligaments; cartilage and bone, adipose, blood Smooth, skeletal, and cardiac muscle Neurons and neuroglia

Dense CT – provides tendons & ligaments w/ strong, flexible support; has high [fiber]  Dense regular: • Consists of tightly packed fibers arranged in consistant pattern – EXs include tendons, ligaments, & aponeuroses  Dense irregular: • Consists of tightly packed fibers arranged in an inconsistent pattern • Found in dermis, submucosa of the GI tract, fibrous capsules, and deep fascia o Loose CT – (aka areolar CT) contains large spaces separating the fibers & cells, and contains a lot of intracellular fluid Collagen Types: o Type I: most abundant – found in dermis, bone, tendon, dentin, fibrous cartilage, fascias, late wound repair. The #1 (most common) collagen is type I o Type II: mainly in hyaline & elastic cartilage, vitreous body Type II for 2 eyes – (get it…there are 2 I’s.) o Type III: major component of reticular fibers (in skin, BVs, uterus, granulation tissue) – think “three on the (BV)” o Type IV: found in basal lamina of basement MBs – think “four on the floor” o Type V: present in fetal MBs “Type Five to come Alive” o Type X: epiphyseal plate Tendons/ligaments: o Ligament – band of CT (DRCT) that binds bone to bone o Tendon – band of CT (DRCT)that attaches bone to muscle • More specifically, it secures the muscle fascia to periosteum  Aponeurosis = a sheet-like tendon o ***When a tendon or ligament attaches to bone, the attaching fibers are called Sharpey’s fibers (it’s not just in teeth)  These are the periosteal collagen fibers that penetrate the bone matrix, binding the periosteum to bone Fasciculus o A bound group of individual muscle fibers o Fasciculi are the bundles of muscle fibers composing the muscle Fascia o Each muscle is surrounded by fascia, which secures the muscle to a tendon o Composed of dense regular CT (DRCT) Intercellular Junctions: o Six major types of cell junctions in humans:  1) Tight junctions (zonula occludens) • Greatest resistance to substances moving between cells o Think Keep it tight so nothing gets through  2) Intermediate junctions (zonula adherens) • Belt-like – connects two neighboring cells  3) Desmosomes (macula adherens) (Think macules are spots – like macula of the eye or melanotic macule.) • Spot-like – connects two neighboring cells o Tonofibrils (tonofilaments) are found in the desmosome (spinosum???)  4) Hemidesmosomes – intermediate filaments • Spot-like – connects plasma MB of an epithelial cell to the underlying basal lamina o Epithelium anchored to the basal lamina and thus to the underlying CT • Common in stratified epithelium of skin and junctional epithelium of the epithelial attachment • Part of the oral cavity which is directly attached to the periosteum??  Hemidesmosomes to the CT • Bullous pemphigoid: o Involves disruption of hemidesmosomes & consequent separation of the epithelium from the basal lamina  5) Focal contacts • Spot-like – connects plasma MB of a fibroblast to the surrounding CT o Points where actin filaments within the cell are attached to the basal lamina. o These are dynamica and are important in migration of epithelial cells for wound repair.  6) Gap junctions • Specialized areas of cell MB – connects neighboring cells • Communicating junctions • Organized collections of protein channels that allow ions/small molecules to passively traverse between connected cells • Separate from components of the junctional complex • Exist in all multicellular organisms and in almost all cell types • Some exceptions – skeletal muscle (Because you want recruiting ability), RBCs, & freestanding cells such as circulating lymphocytes  Miscellaneous • Adherens jxns – provide strong mechanical attachements bw adjacent cells. They are built from transmembrane proteins Cadherins and Catenins. Catenins are connected to actin filaments. o

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Note: One of the oncogenes frequently found with colon CA is mutated version of a protein that usually interacts with catenins. Loss of functioning adherens may  tumor metastasis. EPITHELIAL TISSUE - Classified according to cell shape & number/arrangement of cell layers - Functions of Epithelium: o Protection, absorption, excretion, and secretion - Types of Epithelium: o Simple squamous epithelium:  Found where diffusion & filtration occur  Endothelium lining BVs & mesothelium lining body cavities  Alveoli of the lungs o Simple cuboidal epithelium:  Collecting ducts, as well as proximal & distal tubules of the kidney  Thyroid follicles  Respiratory Bronchioles o Simple columnar epithelium:  Specialized for secretion or absorption  Lines the majority of the GI system • Small & large intestine, gallbladder, & stomach (epi associated with the tubular part of the GI tract) • There is a distinct epithelium change between the esophagus and the stomach.  Uterine epithelium  Salivary gland striated ducts o Stratified squamous epithelium:  Usually contains cuboidal cells in the deeper layers & squamous cells in the surface layer  This tissue is well adapted for abrasion and protection – most resistant to trauma  Broadest classification of epithelium  Found on skin, linings of mouth, oropharynx, laryngopharynx, esophagus (usually not keratinized), anus, and vagina  When it thickens, rete pegs increase in size, and intercellular bridges become more evident o Stratified cuboidal epithelium:  Ducts of the sweat glands o Stratified columnar epithelium:  Large ducts of salivary glands  Male urethra o Specialized EXs:  Pseudostratified ciliated columnar epithelium: • Respiratory Mucous MB of nasal cavity, paranasal sinuses, nasopharynx, trachea, & bronchial tree o Not the lining of the respiratory bronchioles, which lose their cilia and change to cuboidal and then to squamous • Parts of the male reproductive tract  Transitional epithelium • Stratified tissue that lines the urinary bladder, ureter, and upper part of the urethra • Contains dome-shaped superficial cells that change form when contracted or stretched  When epithelial cells specialize so that a free border is characterized with the presence of microvilli, then the cell possesses either a striated or brush border (not pseudopoda or cilia) •

Epithelium Simple

Pseudostratified Stratified

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Cells Squamous Cuboidal Columnar Columnar Squamous Cuboidal Columnar Varies between cuboidal and squamous

Functions of skin: o Prevention of body dehydration o Synthesis of Vit D o Prevention of pathogen entry o Regulation of body temperature Skin – consists of two principle layers: o Epidermis (outer) – consists of stratified squamous epithelium

Function Diffusion and filtration Secretion, excretion, or absorption Absorption, secretion, and protection Secretion and transport of particles out of air passages Protection, prevents water loss Protection and secretion Protection Permits expansion

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 Develops from embryonic ectoderm  Avascular  Outer cells are dead, keratinized, & cornified o SIDE BAR: Excessively thickened layer of the straum corneum composed of:  orthokeratin (hyperorthokeratosis): ↑ keratin layer without residual nuclei (Normal) and uneven surface (so you need ortho)  parakeratin (hyperparakeratosis): ↑ keratin layer with shrunken (pyknotic) residual nuclei (more even surface) o In denture pt that continually wears them and eroded alveolar bone, the underlying alveolar mucosa is best described as gingival mucosa becoming orthokeratinized mucosa Basement MB: o Thin structure that attaches epithelium to underlying CT in contact w/ the dividing layer of cells o Consists of glycoprotein from the epithelial cells and a meshwork of collagenous and reticular fibers from the underlying CT o Type IV collagen o Contains Hemidesmosomes o Consists of:  Basal lamina – develops from epithelial cells • Basal epithelial cells are most likely to be in mitosis  Reticular lamina – develops from CT o Lamina Lucida/Densa?????? o Dermis (inner) – deeper, thicker layer of the skin  Consists of dense irregular CT  Develops from embryonic mesoderm  Contains • BVs & lymphatics • 5 types of nerve endings o (one Q reads: The dermis contains a wider variety of nerve endings than does the epidermis) • Desmosomes • Mitotic cells  Sebaceous glands • Associated with hair follicles and derived from ectoderm • Not found on palms of hands/soles of feet  Sweat/oil glands and hair follicles  Papillary layer of dermis: • Thin & less fibrous • Has projections (papillae) that extend up toward the epidermal layer (rete pegs) • Finely constructed, thin, loose CT • Contains fibroblasts, mast cells, & macrophages • Elastic fibers are abundant and provide the skin tone  Reticular layer of dermis: • Thick, fibrous, dense irregular CT • Continuous w/ the hypodermis • Reticular fibers are abundant (Type III) • Collagenous fibers & elastic fibers are also present • More fibers & fewer cells than in the papillary layer o Tissue fluid reaches the epithelium in the skin through the ground substance of CT from capillaries Hypodermis: o Subcutaneous layer found beneath the dermis that binds skin to underlying structures  Connects dermis w/ underlying fascia of muscle: o Composed of loose areolar CT, adipose tissue and BVs & and lymphatics  Major site of fat deposition (50% of body fat) • The Q actually asks: Where is fat found? & the answer is NOT dermis; “submucosa” or “CT layers” are options, which works for the hard palate (submucosa), but maybe not the skin…???  Good blood supply Epidermis: (BG Stars Gives Lots of Charity) o Outermost portion of skin – develops from embryonic ectoderm o 1) Stratum Basale (= Stratum Germinativum):  Least cytodifferentiated  Contains cuboidal or low columnar cells that exhibit lots of mitosis  Contains tonofibrils in the cytoplasm  Melanocytes are located here  Forms epithelial root sheath of hair follicle o 2) Stratum Spinosum:

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= prickle cell layer Contains cells called Langerhans cells (unknown function – perhaps immune response - APCs) Malpighian layer denotes the stratum basale and stratum spinosum together In the “prickle cell” layer of sulcular epi, the space in between cells is occupied by a small amount of tissue fluid, NOT keratin or capillaries – keratin is intracellular, capillaries don’t reach here.  THICKEST LAYER??, except for Thick Skin - The following 3 Layers are NOT present in NON-Keratinized Oral Epithelium o 3) Stratum Granulosum:  Contain keratohyalin granules in the cytoplasm (not melanin or keratin granules) o 4*) Stratum Lucidum:  Clear band of cells containing eleidin which is transformed into keratin as this layer becomes part of the stratum corneum  Most prominent in thick skin (palms & soles)  Absent in the thin skin and (orthokeratinized oral mucosa, which is thin skin) • NOT present in the oral cavity o 5) Stratum Corneum:  Composed of closely packed dead cells filled w/ keratin  Thickest stratum corneum is found in the palm  Aka “horny” layer - Some cells of epithelium o Keratinocyte:  Cell type most common in epidermis of skin  Specialized to produce keratin (a protective protein)  Tonofibrils & desmosomes are especially well developed in keratinocytes o Melanocytes: produce melanin o Langerhans cells: antigen presenting cells, part of immune system o Merkel cells: associated w/ nerve endings o Inflammatory cells: lymphocytes, monocytes, neutrophils - Cutaneous appendages: (see Kaplan in Integument chapter for all the details on these) o Eccrine (merocrine) sweat glands o Apocrine sweat glands o Sebaceous glands o Hairs o Nails - Oral epithelium: o Some structures found in the oral mucous membrane:  Basal lamina, lamina propria, keratohyaline granules (deeply stained granules in cytoplasm), stratified squamous epithelium o Covered w/ stratified squamous epithelium  Areas of oral stratified squamous keratinized: gingiva, hard palate (area of mechanical stress) o Permeabilities of oral mucosa:  Sublingual > buccal > palatal  Is based on relative thickness & degree of keratinzation • EX: sublingual mucosa is relatively thin & non-keratizined and thin lamina propia (great for meds) o Sublingual musosa is the thinnest epithelium of the oral cavity o Oral cavity is highly acceptable for systemic drug delivery  Mucosa is relative permeable w/ a rich blood supply  Virtual lack of Langerhans cells makes the mucosa tolerant to potential allergens  Route also bypasses the first-pass-effect & avoids pre-systemic elimination in the GI tract  EX – nitroglycerin tablets given sublingually for rapid absorption  NOTE: alveolar mucosa is similar to sublingual mucosa – appears red due to the numerous BVs & thin epithelial covering o CT of oral cavity (referred to as lamina propria):  Forms mechanical support & carries BVs & nerves  Two layers: • Papillary layer – directly under epithelial layer, more cells, tone • Reticular layer – dense, fibrous layer located under papillary layer  Oral mucosa of the cheek has a thinner lamina propria then the outer surface of the lip o Submucosa:  Located between CT and muscle tissue  Present only in areas requiring a high degree of compressibility & flexibility (cheeks, soft palate) • Kaplan states that it is defined Submucosa, but immovable because it is tightly bound to underlying periosteum • The Anterior part contains much adipose tissue, and posterior part of the hard palate is full of glands o NOTE: the most outstanding difference between the gingiva and the mucosa of the hard palate is the presence of glands CARTILAGE/BONE

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Cartilage is avascular – heals slowly after injury No calcium salts are present – cartilage doesn’t appear on x-rays Can support great weight, yet it is flexible & somewhat elastic o Firmness of cartilage depends on:  Electrostatic bonds between collagen fibers & GAG side chains of matrix glycoproteins  Binding of water to the (-) charged proteoglycan complexes Cartilage has a preponderance of amorphous ground substance over fibers Chondrogenic cells = undifferentiated mesenchymal cells important to growth & development of cartilage Chondrocytes: o Reside in depressions in matrix called Howship’s lacuna. (??I thought Howships lacunae are depressions formed by osteoclasts resorbing bone). o The only blood supply is provided by BVs entering cartilage through the perichondrium o Secrete a hard, rubbery matrix around themselves Three subtypes: o Hyaline  Most common type  Matrix contains many, closely packed, fine collagenous fibers  Has a capsule around the chondrocytes which represents the youngest layer of intercellular substance  Covers & protects bone  Precursor to bone – in long bones, hyaline provides a region for bone to grow in length  Found where strong support & some flexibility are needed  Forms nearly all of fetal skeleton  May grow interstitially, where bone only can grow appositionally  In adults: • Articular cartilage – smooth and slippery, it lines movable joints • Costal cartilages – at the sternal ends of the ribs • Respiratory cartilages – movable external nose and septum, larynx, trachea, and the bronchial walls • Auditory cartilages – external auditory meatus and pharyngotympanic tube  Ground substance of hyaline cartilage is basophilic because it contains sulfated proteoglycans called glycosaminoglycans • GAGs can readily bind & hold water – allows tissue to assume a gelatinous nature resistant to compression and also permit some degree of diffusion • Most abundant GAG is hyaluronic acid o Fibrocartilage  Most closely resembles dense, irregular CT  Matrix contains dense collagenous fibers  Withstands tension & compression  Found in intervertebral discs (vertebra), knee joint, TMJ, & symphysis pubis o Elastic  Matrix contains collagenous & elastic fibers  Similar to hyaline cartilage but the fibers are not as closely packed  More importantly, elastic cartilage contains many elastic fibers (elastin)  Forms the external ear (pinna) and is also found in the epiglottis, the auditory meatus, & larynx Tropocollagen o Protein molecule in BOTH collagen and reticular fibers Perichondrium: o Consists of a fibrous outer layer (connective tissue MB) and a chondroblastic inner layer o Very important to cartilage growth Cartilage growth: o Interstitial – chondrocytes divide w/in cartilage – occurs in epiphyseal plates & articular cartilages. Bones lengthen thru interstitial growth (at the cartilaginous epithelial plates – interstitial growth could not occur anywhere but at the plates). o Appositional – where surface perichondrium lays down new layers – results from differentiation of perichondrial cells. Bones increase in girth thru appositional growth. Mineralization of Bone o All of the following are contributors to the mineralization of bone:  Holes or pores in collagen fibers  Release of matrix vesicles by osteoblasts  Alkaline phosphatase activity in osteoblasts and matrix vesicles  Degradation of matrix pyrophosphate to release an inorganic phosphate group – (is this what Alkaline phosphatase is doing?)  NOT Release of acid phosphatase by osteocytes trapped in lacunae Bone growth:

Appositional – below the periosteum is a fibrous outer layer & a cellular inner layer of osteoblasts, which lay down bone  Because of bone’s rigid structure, interstitial growth is NOT possible o Bone increases in size (width) by way of appositional growth by osteoblasts (Not interstitial) o Do not confuse bone growth w/ bone formation  Bone forms by either endochondral ossification or intramembranous ossification Endochondral bone formation: (Think ENDO like long bones (files, etc.) o Cartilage is precursor for bone in this type of growth o The epiphyseal plate (disc) is a wedge of hyaline cartilage accounting for this increase  The plate is found between the epiphysis & diaphysis at each end of a bone  Cartilage cells of the epiphyseal plate form layers of compact bone tissue, adding to the bone length (by interstitial growth in the cartilaginous epiphyseal plate)  The disc becomes inactive in most individuals by late teens/early 20s o 1° ossification center – near the middle of the diaphysis. Responsible for formation of diaphysis o 2° ossification center – in the epiphysis; forms later. Responsible for formation of epiphysis. o Metaphysis – the region between the 1° & 2° ossification centers. Growing zone of cartilage that separates the epiphysis and diaphysis until adulthood. o The Diaphysis  shaft o Here are the steps, all concise-like:  1) chondrocytes proliferate in epiphyseal plate  2) chondrocytes hypertrophy on diaphyseal side of the area  3) matrix calcifies  4) chondrocytes die  5) osteoblasts lay down layer of primary bone along the bone spicules Zones of the Epiphyseal Plate o Zone of resting cartilage  Nearest to the epiphysis  Chondrocytes are disordered and are not dividing rapidly o Zone of Proliferation  New cartilage is produced by interstitial growth  Multiple chondrocytes stack up forming columns o Zone of Hypertrophy  Chondrocytes Mature and Enlarge – Lacunae also appear swollen  More mature ones are at the diaphysis end and less mature are at the epiphysis end o Zone of calcification  Thin layer of mineralized matrix  Death of hypertrophied chondrocytes occurs and the lacunae are invaded by blood vessels  Osteoblasts from the endosteum, travel with the connective tissue of blood vessels and aggregate on the calcified cartilage surfaces  New bone matrix is deposited by appositional bone growth, then remodeled o

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o *The width of the epiphyseal plate remains constant because as the bone elongates, there is remodeling inside the metaphysis o Bones fuse between 12 and 25 depending on bone and leave an epiphyseal line o Plate closes at age 18?? 24?? Bone Repair o Blood Clot forms

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Bridging callus (A composite mass of tissue that forms at a fracture site to establish continuity between the bone ends; it is composed initially of uncalicifed fibrous tissue and cartilage, and ultimately of bone.)forms Periosteal callus forms New endochondral bone forms NOT new osteons grown across the callus

EMBRYOLOGY General Embryology - Cleavage o Begins w/in 24 hours of zygote formation o With each division, the daughter cells (blastomeres) become smaller (no cell growth) o Compaction – begins w/ the 8-cell stage – blastomeres flatten & are held together by tight junctions o Morula – by day 3 or 4, consists of the 16-32 cells, Solid Mass  The First solid ball of cells to form in the embryo - Blastocyst formation o Blastocele  Fluid begins to accumulate in the intercellular space & forms a central cavity known as the blastocele o Blastocyst  In what stage do the cells start to have an inner cell mass?  Blastocyst  Is the zygote, now free of its zona pellucida  Embryoblast – inner cell mass – projects into the cavity – gives rise to the embryo proper • Which cells turn into the inner layer of the fetus?  I think Embryoblast  Trophoblast – outer cell mass – forms outer epithelial layer – gives rise to the fetal portion of the placenta • Think Troph – i.e. has affinity to travel to uterine wall! - 1st Week: Implantation o Begins by the end of the 1st week o Upon implantation, the trophoblast produces hCG, a hormone that maintains the corpus luteum (which secretes progesterone) • Excessive growth of the trophoblast results in hydatiform moles (hCG) which can fill the uterus and result in fetal death • Also, the trophoblast can form the highly malignant chorionepithelioma, a tumor of the chorionic villi o Ectopic pregnancy – implantation outside the uterus - 2nd Week: Bilaminar disc o Epiblast – primary ectoderm – High columnar cells, during 3rd week  forms ectoderm and mesoderm  form the amniotic cavity – On top o Hypoblast – primary endoderm – Low cuboidal cells  contributes to primary yolk sac (or remaining Blastocyst) – On the bottom - 3rd Week: Trilaminar disc o Primitive streak  Linear thickening of the ectoderm cells  Defines the cephalocaudal axis of the embryo  Delimited rostrally by the primitive node o Epiblast cells invaginate between epiblast & hypoblast – forms the intraembryonic mesoderm o Notochord formation: (Get your Honda acCORD on your 16th birth day)  Day 16 – cells of the primitive streak migrate rostrally & form the tube-like notochordal process  The notochord is a rod-shaped body found in embryos of all vertebrates  Composed of cells derived from mesoderm and defines the primitive axis of the embryo  Found on the ventral surface of the neural tube  The notochord induces the the thickening of the ectoderm to form the neural plate  Turns in to the Nucleus Propulsus o Neural plate begins to form o Buccopharyngeal Membrane Ruptures - What causes the infolding of the “head thing” in embryology? o Neural cells growing OR branchial arch formation?? –I’m 100% sure its form neural cells growing! - 4th – 8th Weeks: Embryonic Period o Week 4 –  For the 4 chambers of the heart begins to beat; upper/lower limb buds begin to form for the 4 limbs, and 4 Visible Branchial Arches

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Neural Plate • The neural plate increases in length as the primitive knot and primitive streak move caudally • Invagination of the neural plate at day 18 forms the neural groove • The edge of each fold is known as the neural crest • Neural tube is formed when the crests fuse, starting at the 4th somite region (neck) and proceeding in cephalic and caudal directions • The cephalic end of the neural tube will eventually dilate to form the forebrain, midbrain, and hindbrain o The spinal cord is formed from the remainder of the neural tube  Nueral crest cells (Ectomesenchyme) • Form Posterior root ganglia, sensory ganglia of the cranial nerves, autonomic ganglia, meninges, Schwann cells, suprarenal cells, and Melanocytes  Head and Tail Folds • The entoderm (endo) germ layer gives rise to the GI and depends on BOTH the cephalocaudal folding and the lateral folding of the embryonic disc in a tubelike fashion • HEAD FOLD • Rapid longitudinal growth of the CNS causes the cephalic and caudal ends to bend and form head and tail folds o As a result the brain comes to lie cranial to the cardiogenic area and septum transversum, which contributes to the formation of the diaphragm. o Part of the yolk sac becomes incorporated into the embryo as the foregut  This cavity opens into the midgut via the anterior intestinal portal and is bounded anteriorly by the prochordal plate, which is known at this stage as the buccopharyngeal membrane • This membrane forms the back of the stomodeum and ruptures at the end of the 3rd week to establish communication between the amniotic cavity and the primitive gut • TAIL FOLD o Blah, blah  Lateral Folds • The continued growth of the somites causes the expanding lateral margins of the embryonic disc to bend ventrally, forming lateral folds o As a result, part of the yolk sac is taken into the embryo to form the midgut o In addition, this folding constricts the initially wide communication between embryo and yolk sac to a narrow, long vitelline duct, which eventually lies w/in the umbilical cord  What causes the infolding of the “head thing” in embryology? • Neural cells growing OR branchial arch formation?? –I’m 100% sure its form neural cells growing! • THIS is why I think the answer to the above yellow question is neural cells growth 3rd-8th week – fetus most susceptible to teratogens Ectodermal derivatives:  Surface ectoderm • Otic placode & lens placode • Epidermis • Hair & nails • Subcutaneous glands • Enamel • Anterior pituitary gland • Mammary glands • Hair, enamel, sweat glands & salivary glands are all derived from ectoderm (dentin is not)  Neuroectoderm: • Posterior pituitary gland • CNS neurons • Oligodendrocytes & astrocytes • Pineal gland  Neural crest: • ANS (e.g., autonomic ganglia) • Sensory ganglia of CNs • DRGs • Meninges • Schwann cells • Adrenal medulla (chromaffin cells) • Melanocytes • Odontoblasts Mesenchymal (mesodermal) derivatives:  CT (bone, cartilage)

 Muscle  Dermis  Urogenital system  Adrenal cortex  Spleen  Serous MBs lining the pericardial, pleural & peritoneal cavities o Endodermal derivatives:  GI system  Thyroid/parathyroids  Thymus  Lungs  Liver  Pancreas  Lining of respiratory tract, bladder & urethra - 10th Week: o Genitalia have M/F characteristics Head & Neck Embryology - Stomodeum = stomatodeum: o Slight depression on the surface ectoderm o Represents the primitive oral cavity o Separated from primitive pharynx by buccopharyngeal MB (oropharyngeal MB)  Composed of ectoderm externally & endoderm internally (no mesoderm)  Covers the stomatodeum  Ruptures at 3 ½ weeks (forming max palatal shelves) o Prochordal Plate  Consists of the endoderm of the roof of the yolk sac and embryonic ectoderm  Does NOT contain mesoderm - Branchial Arches = pharyngeal visceral arches o General features:  A series of rounded mesodermal ridges on each side of head & neck of embryo at 4 weeks • Develop in the 4th week as neural crest cells that proliferate & migrate into the future head & neck region • By end of the 4th week, FOUR well-defined pairs of branchial arches are visible externally o The 5th & 6th are small & cannot be seen on the embryo surface  Each branchial arch contains a cartilaginous bar or rod, a muscular component, an artery, & a nerve  1st-3rd arch play role in formation of face & oral cavity • 1st arch develops into Mn & large part of Mx • 1st, 2nd & 3rd arches play role in tongue development  Contain striated muscle, not from somites  Branchial arches (are SVE – special because they are striated, but not developed from body wall or somites)

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From the above picture, the facial process indicated w/ the letter A gives rise to the secondary palate

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Cartilages of each arch:  1st arch cartilage (M: Meckel’s, Mandible, Malleus, Muscles of Mastication, Mylohyoid) • 1st arch develops into Mn & large part of Mx • A model for the Mn – but does not form any part of Mn o What forms the Mn??  Intramembranous ossification of Meckel’s mmmmmmm

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o Fate is dissolution with minor contribution to ossification o Mandible forms before the maxilla. o Both mandible (except for condyles) and maxilla are mostly formed by intramembranous ossification. • Closely related to development of the middle ear o Ossifies to form the malleus & incus • All 8 muscles innervated by V3 (4 mastication, 2 tensors, anterior belly of digastric, and mylohyoid) • NOTE: CN V supplies the muscles derived from the 1st pair of branchial arches  2nd arch cartilage (Reichert’s) • Closely related to development of the middle ear o Ossifies to form the Stapes (Second Stapes) • Think S  Second, Stapes, Styloid Process, Stylohyoid, Seven (VII) • Forms part of the hyoid bone • Also forms Styloid process of the temporal bone • Also forms the stylohyoid ligament • Stylohyoid muscle is from the 2nd arch • All facial expression muscles innervated by CN VII  3rd arch cartilage • Ossifies to form part of the hyoid bone • Stylopharyngeus muscle • Derivatives of the 3rd arch are innervated by CN IX • Think Pharynx: stylopharyngeus & glosspharyngeal nerve  4th & 6th arch cartilages: • Fuse to form laryngeal cartilages (except for the epiglottis) • All other pharyngeal and laryngeal muscles • XI via X: o Spinal part of XI  Goes to SCM and trapezius o Cranial part of XI  Joins X  Goes to pharyngeal muscles from vagal branches  Goes to laryngeal muscles via recurrent laryngeal  NOTE: CN XII provides GSE fibers derived from the Occipital somites, not any arches • 4th arch: o Most pharyngeal constrictors, Except Cricopharyngeus o THE EXCEPTION  Cricothyroid – which you would think is the area of 6th arch o Levator veli palatini o Innervated by superior laryngeal branch of CN X • 6th arch: o All intrinsic laryngeal muscles (except cricothyroid) – superior laryngeal branch of X o The EXCEPTION  Cricopharyngeus – which you would think is the area of 4th arch o Innervated by recurrent laryngeal branch of CN X  5th arch • Absent (short-lived or not developed) A little more about the arches: (yup, I know, I suck & you’re pissed) 1st Arch:  Divides at 4 weeks embryonic development to form Mn & Mx processes • Mn (except condyles) & Mx are mostly formed by intramembranous ossification  Develops into two prominences or processes: • 1) Mn process (larger) – forms the Mn & lower lip o Mn forms by merging of medial ends of Mn processes during the 4th week (Mn forms before Mx) • 2) Mx process (smaller) – forms the Mx, zygomatic bone, squamous part of the temporal bone, most of upper lip o Mx forms by merging of Mx processes o The upper lip is formed from the Mx processes and medial nasal processes o The medial nasal process form the center of the nose and lateral nasal processes form the ala of the nose o Maxillary teeth are developed from Arch I and a globular process o NOTE: the intermaxillary arch is NOT a derivative of the 1st Arch o The palatine shelf is a medial extension of the Mx process o Lateral palatine processes of Mx process – secondary palate (hard and soft palate) o Primary Palate is formed by the medial nasal processes and join the secondary palate at the jxn of the nasopalatine canal o Lateral cleft lip results from failed fusion of Mx & medial nasal processes

 May be unilateral or bilateral ***Cleft palate – failure of fusion of the lateral palatine processes, nasal septum &/or median palatine process  Most common in Asians  Corners of the mouth • Formed by fusion of Mx & Mn processes  Tuberculum impar: (median tongue bud) • Median, triangular elevation which appears in the floor of pharynx just rostral to foramen cecum • Forms from 1st branchial arch • Gives first indication of tongue development in embryo at 4 weeks  Lateral lingual swellings (two distal tongue buds): • Develop on each side of median tongue bud • Elevations are the result of proliferation of mesenchyme of 1st arch • Swellings fuse to form the anterior 2/3 of tongue (mucosa and all) o Delineated by circumvallate papilla??  Bifid tongue: • Results from lack of fusion of distal tongue buds (or lateral swellings) • Common in South American infants o 2nd Arch:  Copula (helps to form posterior 1/3rd) o 3rd Arch:  Posterior 1/3 of tongue is formed by two elevations: the copula (2nd arch) & the hypobranchial eminence (3rd arch) SIDE BAR: o Bifid uvula:  Results from failure of complete fusion of palatine shelves o

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Pharyngeal pouches: (NOT ARCHES) o Paired evaginations of pharyngeal endoderm lining the inner aspects of the branchial arches in the neck region  NOTE: the parotid gland is NOT a derivative of a pharyngeal pouch  Messed up development of 3rd & 4th pouches→DiGeorge syndrome→leads to T-cell deficiency & hypocalcemia Pharyngeal Pouch 1st 2nd 3rd 4th 5th

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Structures Derived Tympanic MB, audtitory tube, and middle ear cavity, mastoid air cells Lymphatic nodules and palatine tonsils Inferior parathyroid gland, thymus gland (Hassall’s Corpuscles) Superior parathyroid gland, ultimobranchial body which gives rise to parafollicular cells (C cells) of the thyroid gland (produce calcitonin) Rudimentary structure, becomes part of the fourth pouch

Vestibular lamina o Separates lips & cheeks externally & the jaw structures internally in the developing embryo o Outer lamina of the 2 epithelial lamina in embryo that separate the palate from the lip!!!!! Frontal nasal process (prominence): o Produced by the growth of the forebrain o Develops the forehead and nose Nasal placodes o Thickened areas of specialized ectoderm that form on each side of the frontal nasal process o Elevations form at the margin of these placodes o What makes up the nose?  Medial and lateral nasal processes  Two lateral nasal processes form the sides (alae) of the nose  Two medial nasal processes form the bridge of nose, nostrils, philtrum (upper lip), & primary palate (anterior to incisive foramen) o Philtrum  What forms the philtrum?  Medial Nasal Processes with Maxillary processes Lips: o Derived from Mn, Mx, & Medial Nasal processes Tongue: o Derived from 1st, 2nd, and 3rd branchial arches  Anterior 2/3 • 1st Arch • Ectoderm (Mucosa) • Tuberculum impar

• Lateral Lingual Swellings – primary developmental source of mucosa of the anterior 2/3 of the tongue Posterior 1/3 • 2nd and 3rd Arch • Endoderm • Copula (2nd) • Hypobranchial eminence (3rd)  Tongue NOT formed from macula At the jxn of the body and root of the tongue is:  Foramen Cecum • Lies at the base of the V of the sulcus terminalis  Sulcus Terminalis • V-shaped demarcation that separates anterior 2/3 from posterior 1/3  Circumvallate Papilla  NOT Lingual raphe  Remnant of thyroglossal duct. Taste in tongue:  All innervation is from the solitary nucleus  Anterior 2/3: CN VII  Posterior 1/3: CN IX  Extreme posterior and soft palate: CN X 

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ENDOCRINE SYSTEM Exocrine glands – classified according to: o 1) Type of secretion:  Mucous (water & mucin)—buccal glands, glands of esophagus, cardiac & pyloric glands of stomach  Serous (enzymes)—parotid, von Ebner’s glands (Serous ONLY), pancreas & uterine glands  Mixed—submand. & sublingual glands, glands of nasal cavity, paranasal sinuses, nasopharynx, larynx, trachea, and bronchi o 2) Mode of secretion:  Merocrine—only the cell secretory product is released from MB-bound secretory granules – EX: pancreatic acinar cells  Apocrine—secretion of product plus small portion of cytoplasm – EX: fat droplet secretion by mammary gland  Holocrine—entire cell w/ secretory product – EX: sebaceous glands of skin & nose (Think Hol = Whole) o 3) Structure of duct system:  Unbranched—“simple glands” – EX: sweat glands  Branched—“compound glands” – EX: pancreas o 4) Shape of secretory unit:  Tubular—cylindrical lumen surrounded by secretory cells – EX: sweat glands  Acinar (alveolar)—dilated sac-like secretory unit – EX: sebaceous & mammary glands  Tubuloacinar (tubuloalveolar)—intermediate in shape or has tubular & alveolar secretory units – EX: major salivary glands o NOTE: Salivary, sweat, sebaceous, and von Ebner's glands are all exocrine glands Pituitary Gland (hypophysis cerebri): o Master endocrine gland because it controls many other glands through release of tropic hormones  Tropic hormones = hormones that effect the activity of another endocrine gland o Origin:  1) Upgrowth from ectoderm of the stomodeum – roof of mouth (anterior pituitary, glandular portion from oral ectoderm) • Rathke’s pouch – diverticulum developing at 3 wks from the roof of stomodeum (primitive mouth) – grows toward brain o The anterior lobe of the hypophysis develops from Rathke’s pouch  2) Downgrowth from the neuroectoderm of diencephalon—floor of brain (posterior pituitary, nervous portion) o Positioned in the sella turcica of the sphenoid bone directly above the sphenoid sinuses o Structure:  Adenohypophysis = Anterior Pituitary • Pars tuberalis, pars distalis, and pars intermedia • Pars intermedia is an avascular zone lying between the lobes but is considered part of anterior pituitary • Pars intermedia & tuberalis have no proven function in mammals • NO innervation • Contains alpha & beta cells • Hypothalamic-hypophyseal portal blood system – controls rls of anterior pituitary secretions. Does NOT appear to have anything to do with posterior pituitary.  Neurohypophysis = Posterior Pituitary • Pituicytes  Primary cell of posterior pituitary, fusiform cell closely related to neuroglia • Median eminence, infundibulum and pars nervosa • Infundibulum carries important nerve tracts from hypothalamus & substances to act on posterior pituitary

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o The infundibular stalk contains the hypothalamic-hypophyseal tract, which carries axons to the posterior pituitary Consists mainly of unmyelinated nerve fibers!!!

Blood supply  From right & left superior and inferior hypophyseal arteries  Sinusoidal blood arrangement (sinusoidal arrangement of BVs also found in Liver and Spleen)  Forms a rich vascular portal system • Portal has two capillary beds • ***Three portal systems in the body: o 1) Hepatic portal system – 1st capillary bed in intestines & 2nd in the sinusoids of liver o 2) Renal portal system – 1st capillary bed in glomerulus & ???? o 3) Hypothalamus-Hypophyseal portal system – 1st bed in HTh & 2nd in Anterior Pituitary  Carries the Releasing Hormones produced in the hypothalamus to the anterior pit and have them release further hormones Synthesized peptide hormones:  Anterior Pituitary = pars distalis: FLAT PeG • The following tissues would be affected if the anterior lobe of the hypophysis were destroyed: o Thyroid epithelium, zona fasciculata of adrenal gland, interstitial cells of testis, spermatogenic epithelium of testis  NOT adrenal medulla • Hormones released from: o Alpha cells – GH & Prolactin (regular hormones) – Alpha for acidic or Eosionophilic pEg o Beta cells – FSH, LH, ACTH, TSH (all tropic hormones) • Sidenote: The hypophysis is characterized by an anterior lobe w/ alpha & beta cells • Follicle stimulating hormone (FSH): o Development of graafian follicles & estrogens in the ovary o Promotes spermatogenesis in males – acts on sertoli cells to produce inhibin and androgen binding protein • Luteinizing hormone (LH): o Stimulates formation of corpus luteum & progesterone secretion o Stimulates interstitial cells (Leydig cells) of testes to secrete testosterone • Corticotropin (ACTH): o Controls secretion of adrenocortical hormones (glucocorticoids), which affect glucose, protein, & fat metabolism • Thyroid stimulating hormone (TSH): o Controls secretion of thyroxine by thyroid, uptake of iodine, and synthesis • **Melanin Stimulating Hormone (MSH) and Beta-Lipotropin o Secreted from the pars intermedia • Prolactin (Lactotropin): o Promotes mammary gland development & milk production, breast development

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 The mammary glands are under direct control from the hypophysis o Triggered by rising estrogen levels • Growth hormone (GH) – aka ‘somatotropin’: o Growth in general; particularly skeletal system by stimulating aa uptake, protein synthesis, & CHO/fat breakdown o Most plentiful of AP hormones o Fusion of long bone epiphyses determines if excess GH will result in gigantism (children) or acromegaly (adults) o Produced by acidophils in the anterior pituitary  Posterior Pituitary – Neurohypophysis or pars nervosa: • Consists of unmyelinated nerve fibers • Consists of 100,000 axons of the supraoptic and paraventricular nuclei of hypothalamus • Secretes ADH & oxytocin • Hormones are synthesized in hypothalamus & transported in axons to the poster lobe for storage and secretion o Transport occurs via hypothalamo-hypophyseal tract • Antidiuretic hormone (ADH) – aka ‘vasopressin’: o Controls rate of water excretion into urine • Oxytocin: o Helps to deliver milk from glands in breasts to nipples during nursing Thyroid gland: o H-shaped structure – two parts joined by a thin isthmus  The isthmus runs in front of the trachea and contacts it posteriorly o It has rings of epithelial cells surrounding a space filled with colloid o Characterized by the fact that it functions as the controller of general body metabolism o In adults, the site of origin is seen as the foramen cecum o Blood supply –  superior thyroid artery from external carotid, then branches to form the superior laryngeal and enters the thyrohyoid membrane along with the internal branch of the superior laryngeal nerve from the vagus,)  inferior thyroid artery from thyrocervical trunk)  SIDENOTE: Vagus, has both the superior laryngeal nerve and the recurrent laryngeal nerve (BOTH do sensory and muscle) • Pharyngeal branch  Innervates the pharyngeal constrictors except the Cricopharyngeus (VI arch)  THINK Cricos are the ODD balls • Recurrent Laryngeal  Sensory/PS: Everything from the folds down  MOTOR: All the motors of the Larynx except Cricothyroid (IV arch) • Superior Laryngeal  Sensory/PS: (Internal branch) above the folds  MOTOR: (External branch) to the Cricothyroid o Nerve supply – glandular branches of cervical ganglia of sympathetic trunk o Cell types:  Follicle cells: • Synthesize thryoglubulin (from tyrosine), which is stored in colloid of each follicle, and is a precursor to T3 & T4 • When pituitary gland secretes thyrotropin, the colloid becomes active & thyroglobulin molecules are released and taken back into the follicular cells where they become T3 & T4 • Remain inactive at times of low thyroid homrone need – can be activated when necessary for mobilization of colloid found in thryroid • Colloid in the usual thyroid follicle stains acidophilic (PINK) • Metabolically active follicular colloid stains BASOPHILIC  Parafollicular cells: (C cells) • Produce calcitonin – lowers calcium & phosphate levels in blood  Thyroglossal duct – a narrow canal connecting the thyroid gland to the tongue during development • Disappears but persists as the foramen cecum  An upward extension of the thyroid gland could be a remnant of the thyroglossal duct, a pyramidal lobe, or a muscular slip  Cervical cysts in the midline of the neck is from Thyroglossal duct Parathyroid gland: o Four glands – two superior (superior thyroid artery from external carotid) and two inferior (inferior thyroid artery from thryocervical trunk) pairs of glands on posterior (dorsum) of thyroid gland o Develops from 3rd & 4th pharyngeal pouches o Blood supply is mostly from inferior thyroid artery (with contribution from the superior thyroid artery to the superior glands only) o Controlled by blood levels of calicum – NOT TSH o Cell types:  Principal cells (chief cells) – secrete PTH, have clear cytoplasm  Oxyphil cells (acid secreting cells) – granules in cytoplasm, unknown function o PTH:

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 Regulates calcium & phosphate metabolism  It is ESSENTIAL for LIFE  Innervention by superior cervical ganglion (sympathetic)  Low PTH leads to tetany & muscle weakness duel to lack of Ca2+ Pineal gland: o Located in the epithalamus of brain and releases the hormone melatonin o Thought to play role in regulation of sleep-wake cycle, body temperature regulation, and appetite Adrenal gland: o Aka ‘suprarenal gland’ o Embedded in adipose tissue above kidneys o Adrenal Medulla:  Secretes Epi and Norepi  Secretion of Adrenal medulla is NOT ESSENTIAL FOR LIFE (unlike those of Parathyroids, Adrenal cortex, Anterior pituitary, Pancreatic islets (Langerhans)  From neuroectoderm (neural crest cells which differentiate into medullary cells called chromaffin cells) • Same embryologic origin as sympathetic ganglia • So, chromaffin cells of adrenal medulla secrete catecholamine • So, the adrenal medulla is an endocrine gland of ectodermal origin in the abdomen  Is composed of many cells containing MB-bound osmiophilic granules  Has an intrinsic stroma consisting primarily of reticular fibers  NOT separated from the cortex by a capsule of collagen fibers o Adrenal Cortex:  Outside to In: Zona Glomerulosa→Zona Fasiculata→Zona Reticularis (GFR – like Glomerular Filtration Rate) • Also outside→in: Salt→Sugar→Sex (aldosterone→glucocorticoids→androgens)  life gets sweeter  Each Zone of the cortex has endocrine cells: • Zona Glomerulosa o Thin layer, clusters of cells beneath CT capsule o Secretes mineralocorticoids, primarily aldosterone • Zona Fasiculata o Thick middle layer, cells arranged in parallel columns that run at right angles to surface o Secretes glucocorticoids, primarily cortisol; also small amounts of estrogenic & androgenic-like substances • Zona Reticularis o Inner layer, cells arranged in interconnecting cords o Secretes small amounts of cortisol & Dehydoropiandrosterone (DHEA)  Derived from the mesoderm Hormones that are ESSENTIAL FOR LIFE: parathyroid, adrenal cortex, anterior pituitary, pancreatic islets (Langerhans) Thymus: o Major gland of immune system o Two soft, pinkish-gray lobes lying in a bib-like fashion below the thyroid gland and above the heart  Encapsulated o From 3rd branchial pouch o Primary lymphoid organ (just like spleen, tonsils, lymph nodes, & Peyer’s Patches) o Site of T-cell maturation o Outer cortex – contains primarily lymphocytes o Inner medulla – contains T-lymphocytes & Hassall’s corpuscles (thought to be vestiges of epithelium – unknown function)  Are Mature in the Medulla o The thymus is the immune system organ most isolated from blood o Master organ in immunogenesis in the young – some believe it monitors total lymphoid system throughout life o Requires zinc – most critical – involved in all aspects of immunity: Vit B6, Vit C, carbonic anhydrase, & others o No afferent lymphatics of lymphatic nodules – it makes mature T-cells, it doesn’t collect them, so it only needs blood supply. o Blood from the internal thoracic & inferior thyroid arteries o Innervated by vagus & phrenic nerves o Has double embryologic origin:  Lymphocytes derived from hematopoietic stem cells (mesenchyme)  Hassall’s corpuscles (epithelium) derived from endoderm of 3rd pharyngeal pouch o Produces thymopoietin & thymosin  Both are thymic lymphopoeitic factors – confer immunological competence on thymus-dependent cells & induce lymphopoiesis  Also produces thymic humoral factor (THF) & thymic factor (TF) • Important in normal development of immune system→proliferation & maturation of T lymphocytes Pancreas: o Has both exocrine & endocrine function

Retroperitoneal organ, except for small portion of tail which lies in the lienorenal ligament Head & neck nestle in the curve of the duodenum; body is behind stomach; tail extends to spleen Characterized by groups of special cells scattered among glandular alveoli Endocrine (pancreatic islets – Islets of Langerhans)  Endocrine glands – secrete products (hormones) into interstitial fluid to diffuse into capillaries→bloodstream  *Alpha cells—glucagon  *Beta cells—insulin, carb metabs, most abundant (80% of cells) • Degeneration of Islets of Langerhans leads to diabetes mellitus  *Delta cells—somatostatin – acts locally w/in islets of Langerhans to depress secretion of insulin & glucagon o Exocrine (acini):  Exocrine glands – secrete products into ducts, Trypsinogen  Centroacinar cells—pancreatic juices – lipases, carbohydrases & proteases (to digest fats, CHOs, & proteins)  Centroacinar cells are ONLY found in the Pancreas o Duct of Wirsung:  Main excretory duct – begins at tail & joins common bile duct to form hepatopancreatic ampulla (ampulla of Vater) • Ampulla opens into duodenum (into descending portion [2nd part] of duodenum) o Accessory pancreatic duct (Santorini’s duct) – opens separately into duodenum (when present) Wolffian duct: (mesonephric duct) embryonic duct that develops in the male into the deferent duct, in the female it is obliterated SALIVARY GLANDS:  Major salivary glands are compound tubuloalveolar glands  Innervation • By way of General Visceral Efferents from both the salivatory nuclei & the lateral horns of the spinal cord o Adenomere: part of developing salivary gland destined to become responsible for function  Composed of: • Intercalated ducts – transport saliva to larger ducts • Striated ducts – o contain mitochondria for electrolyte & water transport; simple, low columnar epithelium o Striations of salivary glands are related to a combo of foldings of basal cell MBs & radially arranged mitochondria • Glandular cells – synthesize glycoproteins o Serous demilunes:  A mucous tubuloalveolar secretory unit that contains lysozyme (degrades bacterial cell walls)  Serous demilune cells: associated w/ mucous acini of the sublingual & submandibular glands (Mixed serous)  Secrete into intercellular canaliculi, not into striated ducts o Mucus cells:  Function to protect & lubricate for transportation  Characterized by large, clear secretory granules that occupy most of the cell & a flattened nucleus-containing, condensed chromatin at cell base o Serous cells:  Rounded euchromatic nucleus surrounded by rough ER in the basal third of the cell w/ zymogen granules (clearly visible & easily stained secretory granules) at cell apex • NOTE: there is an abundance of zymogen granules in the apical cytoplasm (NOT ribosomes or mitochondria) • Apical granules in the parenchyma of the salivary gland cells represents secretion precursors  Serous cells are found in acinar cells of pancreas, parotid, gastric chief cells and intestinal paneth cells (found at base of vili in intestines) • What is common among the pancreas and parotid?  They both have serous secretory cells o Ducts:  Parotid → Stenson’s duct  Submandibular → Wharton’s duct  Sublingual gland → Rivian ducts (Bartholin duct -- See below) o Parotid gland:  Largest salivary gland  PURELY SEROUS • High in amylase activity  Distinguished by having serous acini only, realtively long secretory ducts, and long intercalated ducts • No serous demilunes  Divided by Mn ramus into deep & superficial lobes  PS secretomotor from CN IX by way of lesser petrosal nerve, the otic ganglion, & auriculotemporal nerve (branch of V3) • Diminished salivation due to middle ear involvement most likely involves the lesser petrosal nerve  Lymphatics – superior deep cervical nodes  Stenson’s duct – crosses masseter m., pierces buccinator m. & opens into vestibule opposite Mx M2  Things that PASS through the Parotid Gland • Facial Nerve (NOT Artery OR Vein) o o o o

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Retromandibular vein – originates in parotid gland External Carotid artery Superficial temporal artery Branches of the great auricular nerve o Sensory loss in the skin overlying the parotid gland could be caused by damage to the great auricular nerve (C2-3)  Surgical excision of the parotid gland endangers the facial nerve, auriculotemporal nerve, & external carotid artery Submandibular gland: (formerly ‘submaxillary gland’)  Mixed serous & mucous  Located in the submandibular triangle (digastric triangle)  Superficial part rests on mylohyoid muscle • To expose, you only need to cut the mucous membrane  Deep part is located around the posterior border of mylohyoid between the mylohyoid m. & hyoglossus m. – p.567 ECA  Wharton’s duct • Arises from deep portion of gland & crosses lingual nerve in the region of the sublingual gland – p. 565 ECA • Runs anteriorly immediately deep to the mylohyoid muscle • Terminates on the sublingual caruncle (papilla) adjacent to the base of the sublingual frenulum o Sublingual caruncles are elevations that lie on either side of the lingual frenum  SIDENOTE: The lingual frenum is attached to the genioglossus  Facial artery enters the submandibular triangle deep to the posterior digastric & passes under to supply submandibular gland • Gives off submental branch as it emerges beneath the gland – this is what actually supplies SM gland  PS secretomotor fibers leave CN VII in chorda tympani - which joins the lingual nerve  SM ganglion. • Carries pre-G fibers to lingual nerve from which the submandibular ganglion is suspended • Fibers leave lingual nerve & synapse in ganglion w/ post-G • Also supply sublingual, lingual, von Ebner’s & inferior labial glands & glands of inferior portion of buccal mucosa  Post-G sympathetic fibers are from superior cervical ganglion • They gain access via the adventitia of the facial & lingual arteries o Submandibular & sublingual lymph drainage is to the deep cervical lymph nodes o Sublingual gland:  Contains mostly mucous w/ some serous demilunes  Bartholin’s Duct – major sublingual duct – opens on sublingual papilla in floor of mouth (accompanies submandibular duct)  Mylohyoid muscle supports the glands inferiorly  Innervated by PS of CN VII w/ chorda tympani from submandibular ganglion  Blood from sublingual artery (from lingual a. from external carotid a.) o Von Ebner’s glands:  Located around the circumvallate papillae of the tongue  Function – rinse food away from papilla after it has been ‘tasted’  PURELY SEROUS o Parotid & Von Ebner’s are the only adult salivary glands that are purely serous o Mucus-secreting glands  Palatine gland and Buccal glands (PURELY MUCOUS)  Submandibular (submax)  Sublingual – NOT purely mucous – has some serous demilunes in it.  Mucus of the trachea  Glands of the esophagus • NOT parotid gland or mucosa of ureter Parasympathetic innervation controlling salivation originated ONLY with VII and IX Fordyce’s Granule o Aberrant sebaceous glands • • • •

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GASTROINTESTINAL SYSTEM Divisions: o Foregut – esophagus, stomach, duodenum, liver, gallbaldder, pancreas  Celiac artery o Midgut – jejunoileum, cecum, ascending colon, transverse colon  Superior Mesenteric Artery o Hindgut – descending colon, sigmoid colon, superior 1/3 of rectum  Inferior Mesenteric Artery Peritoneum: o Single sheet of simple squamous mesothelium that lines the abdominopelvic cavity and covers the abdominal and pelvic organs o Parietal layer – portion on the cavity wall

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o Visceral layer – portion on the organ o Some of the organs are suspended from the body wall by a double fold of peritoneum called a mesentery o Some organs are moved to or develop behind the peritoneum, hence retroperitoneal Intraperitoneal structures: (IT’S GLASS J) o Usually have a mesentery or peritoneum  ileum, transverse & sigmoid colon, gallbladder, liver, appendix, spleen, Stomach, and jejunum Retroperitoneal structures: (PADUA Is DARK) o Organs do not have mesenteries o Structures on posterior abdominal wall are retroperitoneal:  Think all “Vertical” Organs and the Pancreas  Duodenum, ascending & descending colon, rectum, kidney & ureters, pancreas, suprarenal glands, IVC, and abdominal aorta  NOT – liver, spleen, … Parts of the large intestine in sequential order – alternate between intra- & retroperitoneal: o Ascending colon (retro)→transverse (intra)→descending (retro)→sigmoid (intra)→rectum (retro)  Vagus nerve innervates ascending colon (but does not innervate the descending colon, sigmoid colon, rectum or anus) Esophagus: o 10 inches, behind trachea in thorax, empties in cardiac portion of stomach through cardiac orifice o Upper 1/3 has skeletal , Middle 1/3rd has skeletal + smooth muscle; lower 1/3 has smooth muscle only  What type of muscle is present in lower 1/3rd  Smooth  Divided into 3 portions on basis of muscularis externa o Receives blood from inferior thyroid artery, branches of descending thoracic aorta, and left gastric artery o PS from esophageal branches of CN X o Motor fibers from recurrent laryngeal of CN X & S innervation from esophageal plexus Abdomen – divided into 9 regions by 4 imaginary planes (Hollywood Squares, Tic-tac-toe): o 1 Epigastric—midline region above umbilical region (contains most of stomach)  2 Hypochondriac—region to R & L of epigastric region. Located beneath the cartilage of the rib cage (spleen here) o 1 Umbilical—located centrally, surrounds the umbilicus  2 Lumbar—areas to the R & L of umbilical region o 1 Hypogastric (pubic)—midline region directly below the umbilical region  2 Iliac (inguinal)—regions on R & L of hypogstric region Stomach: o In upper part of abdomen, extending below the left costal margin into epigastric & umbilical regions, protected by lower ribs o Connects w/ esophagus via cardiac sphincter & to small intestine via pyloric sphincter  The purpose of the Gastroesophageal sphincter is to prevent reflux of stomach contents o 1.0 L capacity o Receives blood from all 3 branches of celiac artery (L & R gastric, short gastric, and L & R gastroepiploic a.) o Venous Drainage from the Portal vein & Splenic Vein o Stomach regions:  Cardiac—lies near junction of stomach & esophagus  Fundus—enlarged portion above and left of esophageal opening into stomach  Body—middle or main portion of stomach  Pyloris—lower portion, lying near small intestines o Rugae – transient folds of the mucosa & submucosa – present in an empty stomach but smoothen out in a distended stomach o Gastric glands of stomach in the lamina propria:  Parietal (oxyntic)—in fundus & body, secretes 0.16 M HCl and Gastric Intrinsic Factor • pH of stomach is 1 million nephrons per kidney o Made up of a renal corpuscle, proximal convoluted tubule, loop of Henle, & distal convoluted tubule  Renal corpuscle aka Malpeeeeegian Corupuscle • Consists of a glomerulus (network of parallel capillaries) & the surrounding Bowman’s capsule • Site of filtration (passage of plasma substances from glomerulus into Bowman’s capsule) o BP forces fluid into Bowman’s capsule  Bowman’s capsule has simple squamous epithelium (parietal layer)  Also has a visceral layer – formed by podocytes  Where do you find podocytes?  Glomerular epithelium  Between the layers is the urinary space  Renal tubule • Four regions: o 1) Proximal convoluted tubule in cortex o 2) Loop of Henle in medulla  Thin limb – Simple squamous  Thick limb – Simple cuboidal o 3) Distal convoluted tubule in cortex o 4) Collecting duct in medulla (Technically not in the nephron) • After filtration, the tubules handle tubular reabsorption & tubular secretion o Water, glucose & sodium are reabsorbed into blood o Waste products are retained & emptied into collecting tubule→ureters Juxtaglomerular apparatus: o JG cells  Modified smooth muscle of afferent arteriole  Secrete renin in response to low renal BP, low Na+, & high sympathetic tone • Renin converts circulating angiotensinogen into AT I, which is then converted into AT II by ACE  Also secrete erythropoietin

Macula densa  Na+ sensor  Part of distal convoluted tubule o Afferent arteriole o Polkissen cells Ureters: o Long, slender, muscular tubes that transport urine from renal pelvis to base of the urinary bladder Urethra: o Fibro-muscular tube that carries urine from urinary bladder to outside of the body o In males it carries semen as well as urine (if you’re lucky) Urinary bladder: o Distensible sac situated in pelvic cavity posterior to the symphysis pubis o Slightly lower in females than in males o Concentrates urine & serves as a reservoir o Tonically Contracted Urine: o Adults pass ~1.5 quarts of urine each day o Volume of urine formed at night ≈ ½ that formed during day o Normal urine is sterile – contains fluids, salts, & waste products, but is free of bacteria, viruses & fungi o Bladder tissues are isolated from urine & toxic substances by a coating that discourages bacterial attachment & growth on walls o

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I know…it’s HOT. TEETH

Enamel Mineral (inorganic) content Color Formative cell

96%

Embryology

Epithelial (ectoderm) NOT mesenchyme No replacement, some reminerilazation Wear, staining, caries

Repair Aging

Translucent yellow Ameloblast

Comparison of Tooth Tissues Dentin Cementum 70% 50% Light yellow Odontoblast – From Pulp Ectomesenchyme

Lighter yellow Cementoblast from PDL Ectomesenchyme

Physiologically, reparative 2°dentin Increased 2° & sclerotic dentin

New cementum desposition Increased amount w/ age (apex)

Pulp None, except denticles or pulp stones Blood red Dental papilla Ectomesenchyme Can recover from mild inflammation Reduces in size; may be obliterated

Sensitivity Cells in mature tissue

None None

Yes, only as pain Cytoplasmic extensions from odontoblasts

No Cementocytes

Yes Odontoblasts & other types

 ENAMEL:  Hardest tissue in body  Richest in calcium – highly mineralized  Secreted by ameloblasts – totally acellular • Enamel has no possibility of self-repair because its formative cells are lost once it is completely formed  Content: • 96% inorganic minerals of calcium and phosphorous as hydroxyapatite (HA) • 1% (or 2%) organic material (protein which is rich in proline) • 3% water  Maturation of enamel is characterized by an increase in inorganic content & a decrease of BOTH water & organic material  Ectodermal origin (NOT ectomesenchymal) • ALL other tooth components are derived from ectomesenchyme  Enamel rod or prism:  Fundamental morphologic unit of enamel  Bound together by an interprismatic substance (interrod substance)  Each is formed in increments by a single ameloblast • At the time enamel matrix is first formed in a tooth, the nuclei of ameloblasts move to the non-secreting end of the cell • Ameloblasts have short extensions towards the DEJ called Tomes’ process when they are in their Secretory stage • These Tomes’ processes give the ameloblasts at the DEJ a “picket-fence” appearance • The Tomes processes from the enamel are picketed with enamel spindles of the dentin (odontoblastic processes) ♦ CAREFUL, Odonotblastic processes are Called Tomes FIBERS  During Calcification, Ameloblasts get their nutrients from the Stellate Intermedium  The interface between pre-ameloblasts and pre-odontoblasts is most like the interface between Epi and Dermis???  Rods begin at DEJ & extend to outer surface • Rods normally diverge radially away from the DEJ ♦ Exception: in the cervical portion of primary teeth, the rods diverge toward the occlusal • Enamel rods converge toward the surface in the area of fissures – although they are still diverging from the DEJ  5-12 million rods per crown  Rods increase in diameter (4 up to 8 microns) as they flare outward from DEJ  Oldest enamel in a fully erupted tooth is located at DEJ underlying a cusp or cingulum  Is a good thermal insulator  Organic matrix decreases as tooth matures and inorganic increases (F– & Zn are minor constituents)  Optically clear in a demineralized histologic section of a adult tooth due to low organic (high inorganic) content  Extremely brittle, but very strong in compression – can endure crushing pressure of ~100,000 psi  Coupled w/ dentin has cushioning property  Semitransluscent – yellow to grayish-white  Selectively permeamble MB allows water & certain ions to pass via osmosis (Remember Bleaching!)  Crystals (Inorganic)  Have their long axes parallel to the rods in the bodies of the rods & deviating increasingly in their tails • Their tails are at the surface, heads at the DEJ

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The degree of calcification in C, compared to that of D, is…lower  This would be opposite for a x-section of dentinal tubule

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Fluoride Topical Application  Acid solubility of the surface enamel is reduced by fluoride Enamel Caries  Are thought to penetrate along the route of the rod sheath Hunter-Schreger bands: (Everyone’s TIGER hunting riffles are pointed in different directions)  Refers to alternating light & dark lines seen in dental enamel that begin at the DEJ & end before they reach enamel surface  They represent areas of enamel rods cut in cross-section dispersed between areas of rods cut longitudinally 

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Lines of Retzius: (Stria) (A) (Think Age Bands like a tree)  Artifacts in enamel (not found in dentin) created by incremental steps of Ameloblasts  Analogous to Contour Lines of Owen in Dentin  Have increased organic content and are indicative of the rhythmic variation in the calcification of the enamel matrix  They follow the appositional growth pattern • Neonatal line: 1985 Q87 ♦ One of the lines of Retzius is accentuated ♦ Marks the division between enamel formed before & after birth ♦ Found in decidous teeth and cusps of permanent 1st molars  Found in enamel of primary incisors, permanent canines, and permanent 1st molars???  Found in dentin of permanent mandibular incisors and permanent first molars??? (Check Calcification ages) • Perikymata: (Peri KY jelly) mata = Imbrication lines of Pickerill ♦ Where lines of Retzius terminate on the tooth surface making a small valley traveling circumferentially around tooth ♦ Ribbed surface of the tooth (for your pleasure) • Imbrication Lines of Pickerill: ♦ Depression or grooves formed when growth rings (lines of Retzius) are incomplete at the enamel surface Enamel tufts: (B)  Fan-shaped, hypocalcified structures of enamel rods that project from the DEJ into the enamel proper (unknown function)  Never found at the outer surface of enamel (perikymata, enamel matrix, & enamel lamellae are) Enamel lamellae: (C)  Defects in the enamel resembling cracks or fractures which traverse the entire length of crown from surface to DEJ  Contain mostly organic material & may provide pathway for bacteria to enter  Hypomineralized structures extending from the DEJ to the surface of the enamel ♦ A = Stria of Retzius; B = Enamel Tuft; C = Enamel Lamella; D = DEJ  

Gnarled Enamel: (A) Below  Found most frequently in cusps, (pits and fissures?)  Wavy Enamel spindles: (B?) Below  Careful, it’s not enamel, IT’S a dentinal process  Elongated odontoblastic processes (hair-like) that traverse the DEJ from the underlying odontoblasts  May serve as pain receptors  In a ground section of a permanent lateral incisor, the enamel spindle is the first formed (other options were: perikymata, gnarled enamel, granular layer of Tomes) • Enamel spindle (dentin) formation happens BEFORE Granular layer of Tomes(mineute areas of interglobular dentin subjacent to cementum)  Serve as the counterparts to the Picket-Fence DEJ from the odontoblast side (Tomes’ processes from ameloblastic side)

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Primary Enamel Cuticle (aka Nasmyth’s MB) – (Think Cellophane wrapping)  Delicate MB covering the crown of a newly erupted tooth  Produced by the ameloblast after it produces the enamel rods  Worn away by mastication and cleaning  Replaced by an organic deposit called the pellicle • Pellicle – formed by salivary glycoproteins & invaded by bacteria to form plaque **In a newly erupted tooth, the junction between the tooth surface and crevicular epi is a Basal lamina-like structure between the enamel and the epithelium Eruption:  During the early stage of eruption, the enamel matures  During eruption, the epithelial covering of the enamel unites with the oral epithelium and then degenerates

 DENTIN:  Content:  70% inorganic (calcium hydroxyapetite), 20% organic (primarily Type I collagen), 10% water  More mineralized than regular bone, but less than enamel  The apatite crystal is oriented parallel to the collagen fibers in the dentin matrix (not parallel to dentinal tubules)??? Purposes of Dentin:  Nutritive—keeps organic components of the surround mineralized tissue supplied w/ moisture and nutrients  Sensory—extremes in temperature, pressure, or trauma to the dentin or pulp are perceived as pain • Pain originates in the pulp due to free nerve endings about the odontoblastic cells ♦ *NOTE: in peripheral organs, the free nerve endings are receptors stimulated by pain (not touch, pressure, temp…)  Protective—formation of reparative or secondary dentin • Theory of Pain ♦ Hydrodynamic phenomena involving fluid influx into the tubules which then stimulate receptors in the pulp Formation  Formed from the dental papilla (so is dental pulp)  Mesenchymal dental papilla adjacent to the IEE differentiates into odontoblasts  Main cell is the Odontoblast, derived from ectomesenchyme • Cell body is in the pulp cavity ♦ **Ectomesenchyme is the primary source of cranial connective tissue  Odontoblasts begin dentin formation before enamel formation by the ameloblasts • During the last part of active eruption the odontoblasts are still functioning actively (ameloblasts are not) Incremental lines of von Ebner (smaller versions of ‘contour lines of Owen’):  Lines in dentin that correspond to ‘lines of Retzius’ in enamel. Run at right angles to dentinal tubules.  Also have a neonatal line which marks the transition between dentin formed before & after birth  Contour lines of Owen are larger than incremental lines of von Ebner and represent temporary disturbances in mineralization of dentin. They are due to the incremental apposition of dentin. Types:  Mantle dentin • The 1st formed portion of the dentin • The peripheral portion of dentin adjacent to enamel (DEJ) or cementum (CEJ), consisting mostly of coarse fibers (Korff’s fibers)  Circumpulpal dentin – the remaining dentin • During the lifespan of a multirooted tooth, dentin forms most rapidly on the floor and roof of the pulp chamber  Peritubular dentin (AKA intratubular dentin): • Lines each dentinal tubule – most mineralized dentin; more than intertubular dentin (↑ inorganic salt content)  Intertubular dentin: (in between tubules) – main bulk of dentin. • Surrounds the peritubular dentin, less mineralized (has ↓ content of inorganic salts). More than 50% organic.  Interglobular dentin: • Imperfectly calcified matrix of dentin situated between the calcified globules near the periphery of the dentin  Primary dentin: • Dentin forming the initial tooth shape • Deposited before completion of the apical foramen  Secondary dentin: • Dentin formed after completion of the apical foramen

Formed at a slower rate than primary dentin as functional stresses are placed on a tooth Does not contain cells (primary cementum & cancellous bone BOTH do) A regular & somewhat uniform layer of dentin around the pulp cavity ♦ Junction between 1° & 2° dentin is characterized by a sharp change in direction of dentinal tubules  Reparative dentin (Tertiary dentin): • Formed very rapidly in response to irritants such as attrition, abrasion, erosion, moderately advancing dental caries, trauma • Forms at the pulp interface of the dentin in response to caries  Sclerotic dentin: • Results from aging & slowly advancing dental caries • The dentin tubules become calcified & obliterated, which blocks access of irritants to the pulp by way of tubules Slide  Dentin tubules appear dark/black due to air when sectioning Dentinal Tubules  Dentinal tubules are S-shaped in the crown due to crowding of the odontoblasts  Each dentinal tubule contains the cytoplasmic cells of an odontoblast  Primary curvatures of the dentinal tubules is LESS in root dentin than in crown dentin – just memorize it  Tomes’ fibers: (AKA Odontoblastic Fiber)  CAREFUL, Ameloblasts give off Tomes Processes • Long, slender, cytoplasmic extension arising from each odontoblast • Occupy the dentinal tubules • Dentin sensitivity is mediated by these fibers • Because of these fibers, odontoblasts are considered living tissue  Dead tracts: • Groups of dead, coagulated cytoplasmic processes of the dentinal tubules • Attributed to aging, caries, erosion, cavity preparation, or odontoblastic crowding • Shows up dark on ground section of tooth • A dead tract can form if odontoblastic processes disintegrate & leave open dentinal tubules DEJ  Morphology of DEJ determined at the Bell stage • “For whom, the BELL TOMES!”  Interface between dentin & enamel  Where calcification of a tooth begins  Oldest dentin is next to DEJ • • •

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 CEMENTUM:  Slightly softer & lighter in color (yellow) than dentin  Avascular and not innervated  Cementum is formed by cementoblasts from the PDL, as opposed to dentin which is formed from odontoblasts of the pulp  In order for cementum to form during root development, the epithelial root sheath (Hertwig’s) must be fenestrated or the continuity must be broken  Lines the apical foramen of a fully developed permanent tooth (Important for ENDO, don’t perf the cementum)  Content:  50% inorganic (HA), 40% organic (collagen/protein), & 10% water • Similar to bone in the degree of mineralization • Collagen fibers formed from BOTH cementoblasts AND fibroblasts  Most closely resembles bone (more so than dentin) except there are no Haversian systems or BVs  Distinguished from enamel by presence of collagen fibers and the cellular component in mature tissue  Distinguished from dentin in that dentin was made by pulp cells and cementum by PDL cells  Similar to bone in that both contain cells in lacunae with canaliculi extending toward nutritional source  Secondary dentin does not contain cells  Cementum does NOT contain blood vessels  Important in orthodontics:  More resistant to resorption than alveolar bone, permitting orthodontic movement of teeth w/out root resorption  Two types of cementum (no functional difference)  Acellular cementum: • Usually predominates in the coronal 2/3 of the root. Thinnest at the CEJ  Cellular cementum: (Think C for laCunae) • Contains cementoblasts, inactive cementocytes, fibroblasts from the PDL, and cementoclasts • Occurs more frequently on the apical 1/3 of the root ♦ Remember you need active Cementoblasts for attrition wear replacement • Usually the thickest to compensate for attritional wear of the occlusal/incisal surface & passive tooth eruption

• Best diffrentiated from acellular cementum by the presence of lacunae (not by any functional difference) Cementoid:  Peripheral layer of developing cementum (uncalcified)  Cementicles:  Calcified bodies sometimes found lying free w/in the PDL or fused w/ the cementum of the tooth  Primary cementum  Possesses lamellae (not lacunae, canaliculi, or cementocytes)  Functions:  Main function – provides rough surface for attachment of Sharpey’s fibers (PDL)  Compensates for loss of tooth surface due to occlusal wear by apical deposition of cementum throughout life (apposition of apical cementum)  Protects the root surface from resorption during vertical eruption & tooth movement  Reparative function of cementum – allows reattachment of CT following periodontal treatment • Replaces resorbed dentin or cementum  Pulp  Mature Pulp is composed of primarily Loose CT  25 yr old has pulp characterized as Loose CT  Anatomy  Derived from Dental Papilla (mesoderm) • After the tooth is formed, the dental papilla remains as the dental pulp  Coronal pulp • Located in the pulp chamber and pulp horns  Radicular pulp • Located in pulp canals  Apical foramen • Communicates w/ the PDL • Local resorption/deposition of cementum & local resorption of dentin may change the position/shape of apical foramen  Accessory canals • Extend from pulp canals through root dentin to PDL • Formed by a break in the (Hertwig) epithelial root sheath  Central Zone (pulp proper)—lined peripherally by specialized odontogenic area which has these zones (inner to outer): • Pulpal core – similar to cell-rich zone • Cell-rich zone – contains fibroblasts (most abundant cell type in the pulp) • Cell-free zone (of Weil) – Capillary and Nerve plexus (Plexus of Raschkow) • Odotoblastic layer – contains odonotblasts and lies next to the predentin and mature dentin  Nerve Fibers • Principle types of nerves in the pulp are sympathetic & afferent fibers ♦ Free nerve endings are only type of nerve ending (which is a specific receptor for pain). Therefore, the only type of response the pulp can give is pain regardless of the stimuli (pressure, cold, heat). • Myelinated fibers = afferent • Unmyelinated fibers = vasomotor • Proprioceptors NOT found in pulp.  Age changes in pulp:  Decrease in: • Intercellular substance, water, & cells • Size of pulp cavity due to secondary &/or tertiary dentin • Number of reticulin fibers  Increase in: 

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Number of collagen fibers

Calcifications w/in pulp (called denticles or pulp stones) ♦ Denticles:  True: complete w/ tubule and processes  False: amorphous in structure  Free: unattached to outer pulpal wall  Attached: attached at dentin-pulp interface Pulp capping  More successful in young teeth because: • Apical foramen of a young pulp is large • Contains more cells • Is very vascular • Has fewer fibrous elements •

• More tissue fluid  Note: Young pulp lacks collateral circulation  Alveolar Process  Alveolar bone proper: (aka: cribriform plate or lamina dura) (SOCKET)  Part of alveolar process which immediately surrounds root of tooth & to which the fibers of PDL are attached  Has minute openings which provide passage for vascular nerve components  During growth and development of the alveolar process, osteoblasts, osteoclasts, and osteoid are present  Resorbs when subjected to pressure  What causes alveolar bone development? • Tooth Growth, w/o teeth it won’t grow  Consists of: • 1) Compact lamellar bone • 2) A layer of bundle bone ♦ Sharpey’s fibers insert into this layer  Supporting alveolar bone:  Surrounds the alveolar bone proper & gives support to the socket  Consists of: • Cortical plate (compact lamellar bone) ♦ Forms outer & inner plates of the alveolar processes ♦ Thicker in Mn than Mx • Spongy bone (cancellated bone): ♦ Fills in area between cortical plates of bone ♦ This type of bone is not present in anterior region of mouth – here the cortical plate is fused to the cribriform plate ♦ This is also true over the radicular buccal bone of the maxillary posteriors  NOTE: Alveolar bone proper is the only essential part of the bone socket – supporting alveolar bone is not always present  Mandible  Growth is appositional  Bone can only grow appositionally, but cartilage can grow appositionally or interstitially  Causes the formation of resting lines during growth of Mn  During active tooth eruption there is apposition of bone on all surfaces of the alveolar crest and on all walls of the bony socket???  The bone formed at the base of the socket is usually in the form of horizontal trabeculae  The best theory describing the force needed for active eruption is from the cells and fibers of the PDL pulling the tooth out  Permanent teeth move occlusally and buccally when erupting  Break in the mandible from a baseball at the mental foramen, which way will the muscles pull the fragments  Large  anterior and superior Small  Inferior and Posterior  When you open your mouth, the buccal vestibule is squashed by the Coronoid process  Apical abscesses  Mn M2s & M3s have a marked tendency to produce cervical spread of infection most rapidly  Attachment of muscles may determine the route that an infection will take, channeling the infection into certain tissue spaces  Mandibular Teeth • Infections perforate below the buccinator • Swelling of the lower ½ of the face • Infection will spread medially (lingually) from the Mn into the submandibular space & masticatory spaces • It pushes the tongue forward and upward • Further spread cervically may involve the visceral space and lead to edema of the vocal cords and airway obstruction • Molar abscess will reach the floor of the mouth by continuous spread until the lingual attachment of the mylohyoid m. • Swelling at the angle of the mandible is from the deflection of exudates from the mylohyoid m. • Tooth #32 is infected…infection spreads to parotid, buccopharyngeal, & masseteric fascial spaces, NOT the temporal • In Hep C pt, Tooth #28 needs to be extracted…Which is a life-threatening sequelae of that tx…Ludwig’s Angina ♦ Alpha delta fibers are responsible for sharp pain  Maxillary teeth • Perforate the bone above the buccinator attachment • Cause swelling of the upper ½ of the face (which will eventually spread to the entire face)  Lingual spread • From infected Mn premolar or molar teeth into floor of mouth when above the level of attachment of the mylohyoid m. ♦ This is due to the mylohyoid line position relative to roots of premolars & molars – search it in the Dental Anat file • Below the mylohyoid, it would drain into the submaxillary/submandibular space

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Ludwig’s Angina  Cellulitis, usually of odontogenic origin, bilaterally involving the submaxillary, sublingual, and submental spaces, resulting in painful swelling of the floor of the mouth, elevation of the tongue, dysphasia, dysphonia, and (at times) compromise of the airway – hence the life-threatening part  Mesial Drift (or in mesial tilting during orthodontic movement):  Coronal half of the Mesial root wall shows resorption from osteoclastic activity  Coronal half of the Distal wall of the root shows deposition from osteoblastic activity  Similar situation: loosening & tightening of primary tooth before its lost • Alternate resorption (clasts) and apposition (blasts) of cementum and bone TOOTH HISTOLOGY  First sign of tooth development (seen in histo sections) occurs in 6th week in utero (pictures)  Tooth development appears to be initiated by the mesenchyme’s inductive influence on the overlying ectoderm  In 6th week there is a thickening of the oral epithelium (derivative of the surface ectoderm)  These thickenings or U shaped bands are called the dental lamina and follow the curve of the primitive jaws (20)  At certain point on dental lamina, the ectodermal cells proliferate and produce swellings which become the enamel organ  Inside the depression of the enamel organ is an area of condensed mesenchyme becomes the dental papilla  Surrounding both the enamel organ and dental papilla is a capsule-like structure of mesenchyme called the dental sac  Enamel organ separates from the dental lamina AFTER the layer of dentin is deposited  Each tooth is the product of two tissues that interact during tooth development – 1) oral epithelium & 2) underlying ectomesenchyme  The epithelium grows down into the underlying ectomesenchyme to form small areas of condensed mesenchyme, which become tooth germs  Sequence of Tooth Histogenesis  The ectomesenchyme influences the oral epithelium to grow down into the ectomesenchyme  Elongation of inner enamel epithelium  This triggers the mesenchymal cells to differentiate into odontoblasts  Differentiation of odontoblasts  Deposition of first layer of dentin  Deposition of first layer of enamel  Deposition of root dentin and cementum  Stages of Histogenesis  Initiation (Bud Stage):  Initial interaction between oral epithelium and mesenchyme (ectomesenchyme), formation of dental lamina • Congenitally absence of teeth results from an interruption in this phase  Fused or geminated teeth occur during initiation and proliferation stages of tooth development  Proliferation (Cap stage):  Shape of tooth becomes evident, enamel organ is formed  Differentiation (Bell Stage):  Final shaping of tooth; cells differentiate into specific tissue-forming cells (amelo-, odonto-, cemento-, & fibroblasts) in emanel organ  Histodifferentiation and mophodifferentiation occur during this stage  DEJ determined at this stage – “For whom the BELL TOMES”  Forms the DEJ (the 1st structure formed by tooth but that remains in the fully developed tooth – not IEE)  Apposition:  Cells that were differentiated into specific tissue forming cells begin to deposit the specific dental tissue  **Dentinogenesis imperfecta & amelogenesis imperfecta occur during histodifferntiation  Terms of Dentinogenesis  From Top of Diagram to bottom  Oral Epithelium • Epithelial layer on top  Dental Lamina • Stem connecting the Oral Epithelium to the Enamel Organ  Tooth Germ • Enamel Organ, Dental Papilla, Dental Sac (not successional lamina)  Enamel Organ • Derived from ectoderm • Gives rise to enamel and Hertwig’s Root Sheath • 4 Layers of Enamel Organ (not in order): ♦ 1) Outer enamel epithelium (OEE)  Outer cellular layer  Outlines the shape of future enamel organ ♦ 2) Inner enamel epithelium (IEE)

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 Innermost layer  Cells will become ameloblasts  Essential for the initiation of dentin formation (ameloblasts stimulate dentin formation)  1st formed in a partially erupted central incisor (among 1°/2° cuticles, stellate reticulum, stratum intermedium) ♦ 3) Stratum Intermedium  Lateral to IEE  Essential to enamel formation (nutrients for the ameloblasts of IEE), but does not actually secrete the enamel  Ameloblasts will only form enamel when stratum intermedium is present ♦ 4) Stellate Reticulum  Central core and fills bulk of organ  Contains lots of intercellular fluid (mucous type rich in albumin) which is lost prior to enamel deposition • Disturbances during morphodifferentiation of the enamel organ affect the shape of the tooth • IEE & OEE of enamel organ come together in the neck region and form Hertwig’s root sheath • After enamel formation, all 4 layers become 1 and form the Reduced Enamel Epithelium ♦ The reduced enamel epithelium & oral epithelium fuse to form the initial junctional epithelium ♦ Very important in forming the dentogingival junction, where the enamel & epithelium meet as tooth erupts ♦ This forms initial junctional epithelium (attached epithelium – joining gingiva to tooth)  Dental Sac (aka Dental Follicle) • Derived from mesenchyme (derived from neural crest cells) – NOT from oral epithelium • Gives rise to the cementum, PDL, and alveolar bone proper (aka attachment apparatus) ♦ The embryonic precursor to cementoblasts • Surrounds the tooth germ (enamel organ/dental papilla)  Dental Papilla • Derived from mesenchyme (derived from neural crest cells) • Gives rise to the dentin and pulp • Triangular shaped inside the bell stage under the enamel organ • Peripheral cells of dental papilla differentiate into odontoblasts which produce predentin (calcifies to become dentin) • Center of dental papilla will become dental pulp  Epithelial Diaphragm  Multiple root formation follows unequal proliferation of the epithelial diaphragm – okay Hertwig’s Epithelial Root Sheath  Sheath is formed by the joining of the IEE & OEE  After crown formation, the root sheath grows down  It shapes the root of the tooth & induces formation of root dentin (stimulates differentiation of odontoblasts)  Uniform growth of this sheath will result in the formation of a single rooted tooth  Medial outgrowths or evaginations of this sheath will produce multi-rooted teeth • ???OLD TEST (1987) – The # of roots formed is determined by the number of medial ingrowths of the cervical loop  Hertwig’s epithelial root sheath is characterized by:  1) The formation of cell rests (rests of Malassez) in the PDL when the sheaths functions have been accomplished  2) The absence of stellate reticulum and a stratum intermedium Cementogenesis:  After first root dentin is deposited, the cervical portion of Herwig’s root sheath breaks down  This new dentin comes in contact w/ the dental sac  This communication stimulates cells fibroblast cells from the dental sac to differentiate into cementoblasts which produce cementum  Accessory root canals are formed by a break or perforation in the rooth sheath BEFORE the root dentin is deposited Epithelial Rests of Malassez  Are remnants of Hertwig’s epithelial root sheath  Fate  Some degenerate and others calcify or become ‘cementicles’  Persistent rests can be found as groups of epithelial cells in the PDL  Continuity of Hertwig’s epithelial rooth sheath must be broken in order for cementum to be deposited during tooth development Tomes Granular Layer  Formed by odontoblasts that produce an organic matrix  Found in radicular dentin and lies just beneath the cementum  So, the granular layer (Tomes) makes the root dentin readily distinguished from crown dentin  **Interglobular dentin differs from Tomes granular layer in that interglobular dentin usually occurs a short distance inside the DEJ and represents hypocalcified areas Partial Anodontia (Hypodontia)  Radiograph of 10 year pt where 2 succedaneous teeth are missing

PDL & GINGIVA PDL  0.2mm wide  Thickness depends on:  Age (decrease 0.1mm in old age—due to deposition of cementum & bone)  Stage of eruption  Function of the tooth • (PDL is thin and irregular principle fibers on teeth that lose their function) • Thicker in areas of tension than in areas of compression. (Think – its getting stretched out, so it is going to be taller in these areas. • Thickest in the Apical region of a tooth  Vital to the functional life of a tooth because it:  Contains nervous and vascular elements  Allows for physiologic movement of the tooth  Provides a cellular source for new cementurn and bone  Derived from the dental sac!!!!!  Connects cementum to alveolar bone  Contains remnants of Hertwig’s root sheath (Rests of Malassez—called ‘cementicles’ when calcified)  Sharpey’s Fibers – terminal portion  Diameter greater on bone side vs. cementum  Only consist of Collagenous fibers, NOT reticular or elastic  Insert into Bundle Bone and Cementum  Function of PDL:  Physical  Attachment of tooth to bone via principal fibers  Formative  Formation of CT components by activities of CT cells (cemento-, fibro-, and osteoblasts)  Remodeling  By activities of CT cells (blast vs. clast of above cells)  Nutritive  Through BVs  Sensory  By CN V  Proprioceptive & tactile sensitivity  PDL and its hard tissue anchorage in terms of resisting occlusal force:  Anterior teeth have slight or no contact in the ICP  Occlusal table is < 60% of the overall faciolingual width of the tooth  Occlusal table of the tooth is generally at right angles to long axis  Crowns of Mn molars are 15-20° lingually inclined  Hence roots are positioned more facially for these teeth  Following loss of tooth function:  One may expect a reduction in width & loss of regular arrangement of principal fibers??? • Like pulling a yarn taut???  PDL & nerves  2 Types  Free, unmyelinated endings – convey PAIN – that’s cold test takes a long time to react  Encapsulated, myelinated – convey PRESSURE – Think fast jaw jerk reflex  PDL contains:  Cells  Osteoblasts, fibroblasts, Macrophages, Cementoblasts, etc.  BVs  Lymphatics  Extracellular substance of fibers (gingival and principal)  The principal fibrous elements of the PDL in adults is chiefly collagen  Ground substance  Mostly proteins and polysaccharides  Oxytalan fibers  Related to the microfibrillar component of elastic fibers  Run parallel to root surface  Gingival fibers (5) (picture)  General features: • Collagen fibers that provide support for the marginal gingival including the interdental papilla

• Found w/in the free gingiva. • Continuous w/ the CT fibers and are often considered part of the ligament (PDL)  Circumferential (circular) fibers (A) • Encircle the tooth around the most cervical part of the root • Insert into cementum & lamina propia of the free gingiva & alveolar crest • Resist rotational forces  Transseptal fibers (BELOW A) • Extend from tooth to tooth (cementum to cementum), coronal to alveolar crest • Are embedded into the cementum of adjacent teeth • Not on the facial and no attachment to the alveolar crest • Maintain dental arch integrity • Classified w/ principal fibers of PDL (AKA collagenous fibers). • Are included in the Interdental Ligament  Dentogingival fibers (B) • From the cementum apical to the epithelial attachment; course laterally & coronally into gingival lamina propria  Dentoperiosteal fibers (C) • From the cervical cementum over the alveolar crest to the periosteum of the cortical plates of bone  Alveologingival fibers (D) • Insert in crest of alveolar process and spread out through the lamina propria into the free gingiva •  Principal Fibers of the PDL(5) (picture)  General features: • Composed of Type I collagen • Sometimes classified as belonging to general group of alveolodental fibers • Connect the cementum to the alveolar bone • Never found in contact w/ enamel  Alveolar crest fibers (B) • From cervical cementum to the alveolar crest • Function to counterbalance the occlusal forces on the more apical fibers and resist lateral movement  Horizontal Fibers (C) • Perpendicular from alveolar bone to cementum • Resist lateral forces  Oblique fibers (33%) (D) • Most numerous • Insert into cementum and extend occlusally and obliquely into the alveolus • Resistant to forces along the long axis of the tooth (masticatory) • Found usually in middle 1/3 of root  Apical (E) • Offer initial resistance to tooth movement in occlusal direction  Interradicular fibers (F) • Only in multi-rooted teeth • Extend from cementum in furca are to bone w/in furca area  Gingival apparatus  Term used to describe the 5 gingival fiber types and the epithelial attachment  Gingival Ligament  Includes the dentogingival, alveologingival, and circumferential fibers GINGIVA  The gingiva offers protection against bacterial invasion, the most important factor in this protection being that the surface epithelium is highly impervious  Free Gingiva (aka ‘marginal gingiva’)  Collar of tissue that is not attached to the tooth or alveolar bone  1-3mm wide & forms the soft tissue wall of the gingival sulcus next to the tooth  Extends from free gingival groove to gingival margin  Structures:  Gingival Margin – • 1mm band of gingiva that forms immediate collar around the base of the tooth

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Gingival Sulcus – • Areas between the unattached gingiva and the tooth (where popcorn kernels go) • Above junctional epithelium (JE) – continuous w/ JE, but structurally different • Epithelium is non-keratinized (same w/ gingival col) • Most vulnerable to inflammation • Healthy sulcus should NOT have rete pegs (rete pegs indicate inflammation) • Cells of the sulcular epi are joined TO EACH OTHER by desmosomes  Epithelial attachment – (Junctional epithelium) • As supragingival plaque/calculus continues apically, it first would disrupt the attachment of the junctional epithelium • Joins the gingiva to the tooth • Inner layer of cells of JE attach gingiva to tooth • Cells of the epithelial cuff attach to enamel or cementum by means of hemidesmosomes • Internal basal lamina (**Basal lamina like structure) • Does NOT contain rete pegs as the superior apex of the free gingiva does ♦ **Dentojunctional epithelium  Gingival epithelium that faces the tooth  Includes both Sulcular and Junctional  Interdental Papilla – • Portion of the free gingiva that fills the IP embrasures below contact area • Consists of 2 papillae that are connected by the concave-shaped interdental col ♦ Interdental col  Conforms to the shape of the contact area  Not present in teeth w/o contact  Non-keratinized • Blood vessels of the interdental papilla anastomose freely with BOTH periodontal & interalveolar vessels Attached Gingiva  Part of the gingiva that is attached to the underlying periosteum of alveolar bone & to cementum by CT fibers & epithelial attachment  NO submucosa  Present between the free gingiva & the more movable alveolar mucosa  Parakeratinized (with nuclear remnants in stratum corneum)  Masticatory Mucosa is Parakeratinized except with Dentures  Soft palate, skin of lips, floor of mouth & ventral tongue are NOT parakeratinized  Stippled  Extends from the mucogingival junction to free gingival groove Mucogingival Junction  Separates the attached gingiva and the alveolar mucosa  Joins lining mucosa & masticatory mucosa Free Gingival Groove  Separates the free gingiva from the attached gingiva  Is related to the arrangement of the supraalveolar fibers (not probe depth measurement, alveolar crest, or degree of PD health) Oral Mucosa  Covers all oral surfaces except the teeth  2 Layers:  Stratified squamous epithelium • Keratinized • Nonkeratinized • Parakeratinized  Lamina Propria • CT that supports the epithelium • 2 Layers ♦ Papillary ♦ Reticular • Attached to the periosteum or interposed over the submucosa (glands, BVs, nerves) ♦ In the hard palate & gingiva, the lamina propria attaches directly to bone without an intervening submucosa (not so for the soft palate)  Gingiva differs from alveolar mucosa in that it has high connective tissue papillae Specialized Mucosa  Covers the dorsum of the tongue and taste buds  Non-keratinized (most of the dorsum of the tongue is keratinized, right?) Masticatory Mucosa

 Free gingiva, hard palate, attached gingiva, interdental gingiva  Keratinized  Beneath lies the lamina propria (dense, thick, firm CT containing collagenous fibers)  Lining or Reflective Mucosa  Inside of lips, cheek (buccal mucosa), vestibule, lateral surface of alveolar process, floor of the mouth, soft palate, ventral tongue  Thin, movable  Nonkeratinized, stratified squamous epi  Lamina Propia – no glands in the lamina propria of the floor of the mouth  Submucosa  Periodontium  2 functional units:  Gingival unit • Free gingiva, attached gingiva, and alveolar mucosa  Attachment apparatus • Cementum, PDL, and alveolar bone proper TMJ  TMJ  A diarthrodial joint that has a (fibrous CT- 1996 exam) (fibrocartilage -decks) on its articular surfaces (NOT hyaline)  Most diarthrodial joints are covered by hyaline cartilage  The articular surface of the condyle AND the posterior slope of the articular eminence have the same fibrous CT covering  Joint cavity is lined by a synovial MB & enclosed by a fibrous capsule  Divided into two compartments by an articular disc – ALSO MADE OF FIBROCARTILAGE  The TMJ of a child contains Undifferentiated Mesenchyme cells, then Cartilage layer under the Fibrocartilage  TMJ Nutrients  Hyaluronic acid of the Synovial fluid (produced by synovial membrane), feeding the articular cartilage  12 weeks  condylar cartilage is present at the most superior aspect of the ramus • The condylar cartilage persists as the cartilage zone of the mature condyle, contributing to its adaptation potential  12 weeks  The embryonic CT (Mesenchymal) between the growing condyle and temporal bone condenses to form the articular disc  13 weeks  Cavitation forms the lower joint compartment then the upper compartment  14 weeks  Joint development complete  Structures  Articular Surface of temporal bone  Articular fossa (or ‘glenoid fossa’ or ‘mandibular fossa’) – concave • In older people is covered with Fibrous CT with Chondrocytes • In young adults the articular zone has ♦ Articular zone of Fibrous CT ♦ Proliferation zone of undifferentiated Mesenchymal cells UM ♦ Cartilage zone  Articular Eminence – convex • Is the anterior surface/boundary of the Mandibular (glenoid) fossa  42 yr old female with Hx of hyperPTHism, bilateral pain in TMJ, ears clogged and “ringing” • The region of the articular surface that is most likely missing is the Proliferative zone (I have no idea why!) ♦ See 2001 Pilot Q 366  Condyle  Posterior aspect of the condyle is rounded & convex, whereas the anteroinferior aspect is concave  Posterior aspect of the condyle can be palpated by way of the external auditory meatus  Growth of the condyle allows for the space needed for erupting teeth  Condyle is broken through the pt. fovea?, there is no necrosis, what artery is supplying the tissue?  Superficial Temporal artery  Articular disc (meniscus)  Consists of fibrocartilagenous (Fibrocartilage) tissue, which resembles dense, irregular CT that may be associated w/ chondrocytes, – capable of providing smooth articulating surface  Meniscus is a biconcave oval plate • Divides the joint into two spaces: ♦ Superior joint space – bounded by articular fossa & articular eminence  Sliding Motion – occurs between the disks & articular eminences ♦ Inferior joint space – bounded below by the condyle  Rotational Motion • Meniscus varies in thickness, the thinner, central intermedia zone separates the thicker anterior & posterior bands • Posteriorly, the meniscus is continuous w/ the posterior attachment tissues called the bilaminar zone which is vascular, innervated tissue that plays an important role in allowing the condyle to move forward

NOTE: the bilaminar zone is the most vascular portion of the articular disc (NOT the posterior band) Posterior-inferior lamina of bilaminar zone has a very dense collection of elastic fibers (1999Q23 – confirmed JC?) ♦ Retrodiscal Pad Area  Elastic fibers  Venous plexus – well-vascularized structure of the TMJ  Collagen fibers  Loose connective tissue  NOT Hyaline Cartilage  Nonarticular surfaces of the TMJ are covered w/ synovium or periosteum (don’t get clowned by the “non” part)  Articular capsule  Surrounds the joint  Attached above to the articular eminence (tubercle)  Attached at margins of the mandibular fossa & below the neck of the Mn  Synovial MB lines the capsule in the superior & inferior spaces of the joint – Synovial MB also produces the synovial fluid for the joint. • It does not cover the articular surfaces of articular discs  Innervated (all sensory, no motor) by the Auriculotemporal (posterior portion), the masseteric (anterior), and the posterior deep temporal (anterior as well as temporalis m.) (ALL V3). (Think- information from the MAP)  Ligaments (picture)  Temporomandibular ligament • Is the only ligament that gives direct support to the capsule of the TMJ • Aka: ‘lateral ligament’ • Runs from articular eminence to the Mn condyle • Provides lateral reinforcements for the capsule • Prevents posterior & inferior displacement of the condyle  Sphenomandibular & stylomandibular ligaments • Are considered accessory ligaments responsible for limiting Mn movement • Sphenomandibular ligament – attached to the lingula of the Mn and the spine of the sphenoid bone ♦ Most often ligament damaged in an IA nerve block (tested again & again) • Stylomandibular ligament – attached at angle of the Mn  Muscles  Lateral pterygoid muscle: • Superior head: ♦ Origin: Infratemporal surface of sphenoid bone ♦ Insertion: TMJ capsule & articular disc • Inferior head: ♦ Origin: Lateral surface of pterygoid plate ♦ Insertion: Neck of the Mn condyle • Actions: ♦ Protrude, depress (open), laterally move Mn  Innervation  Auriculotemporal nerve, Masseteric, and Posterior Deep Temporal in the capsule and around the periphery of the disc  NOTE: the auriculotemporal nerve carries pain, touch, temperature, & proprioceptive modalities to the TMJ  The TMJ, as w/ all joints, receives no motor innervation • The muscles that move the joint receive the motor innervations • Branchiometric motor fibers innervate the temporalis, pterygoids, anterior belly of digastric, mylohyoid, & tensors  Treatment  TMJ should be evaluated for tenderness and noise  The joint is palpated laterally (in front of the external auditory meatus) w/ the Mn in closed and open position  The joint is palpated posteriorly (through the external auditory meatus) w/ the Mn in closed and open position  Things to note:  Tenderness and sensitivity  Joint noises  Mn range of motion • Normal range of movement of adult Mn ~50 mm opening & ~10 mm protrusively & laterally  Magnetic resonance imaging (MRI):  Best imaging modality for identifying position of articular disc of the TMJ  Gold standard for soft tissue, especially the position of the articular disc  Utilizes magnetic field to alter energy levels of primarily the water molecules of soft tissue • Results in good visualization of various soft tissues, including articular disc ♦ ♦

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Major advantage of MRI is that there is no radiation involved • No harmful effects have been demonstrated  Panoramic, CT, & lateral transcranial radiographs are used to evaluate the bony structures of the TMJ  Problems  Dislocation (luxation)  May occur w/ one or both condyles  Relaxation of the supporting ligaments occasionally allows condyle to extend anteriorly beyond normal open position  May be manifested by true luxation that requires assistance for reduction • Or, it may be merely an overextended excursion anteriorly that is self-reducing (subluxation)  TMJ can only be dislocated anteriorly  Anteromedial – most common direction in which the articular disc in the TMJ can be displaced  A click sound is usually demonstrated when this happens  Articular disc is seated on condyle & held in place by collateral ligaments (attached to medial & lateral poles of the condyles)  Muscle fibers from the lateral pterygoid muscle are attached to the anterior portion of the articular disc  Reduction of the dislocation  Is done by standing behind pt w/ thumbs inside mouth and the index fingers below chin  Thumbs depress the back of the jaw, and the chin is elevated by the index fingers  The head of the condyle will then slide back into the articular fossa  42 yr old female with Hx of hyperPTHism, bilateral pain in TMJ, ears clogged and “ringing”  The region of the articular surface that is most likely missing is the Proliferative zone (I have no idea why!)  Sounds  Click – best describes sound associated w/ a disc displacement w/ reduction  Crepitation sound (crepitus) – usually associated w/ a degenerative process (osteoarthritis) of the condyle  Dull thud – usually associated w/ self-reducing subluxation of the condyle  Tinnitus – ear ringing -

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BLOOD Fluids in general: o Extracellular fluid (Na-142; K-4) vs intracellular (Na-10 K-140) o Fluid: 50-60% of body weight  Intracellular fluid (w/in cells) = 35-40% of body weight  Extracellular fluid (outside the cells) = 15-20% of body weight • Blood plasma = 4-5% of body weight • Interstitial fluid = 11-15% of boby weight o Transcellular fluids: 1-2 Liters; CSF, intraocular, synovial, pericardial, pleural, peritoneal o Tissue (interstitial) fluid contains a small % of plasma proteins of low MW that pass through the capillary walls as a consequence of hydrostatic pressure of blood. This fluid bathes the cells Blood o 8% of total body weight o Volume = 4-6 liters o Temp = 38°C o pH = 7.35-7.45 Blood composition o 55% plasma:  91% water  7 % protein • Albumins – 55% • Globulins – 38% • Fibrinogen – 7%  2% other solutes • Metabolic end products, food materials, respiratory gases, hormones, ions o 45% formed elements:  1) Erythrocytes – 4.3-5.8 million/mm3 • Proerythroblast → erythroblast → normoblast → reticulocyte → erythrocyte • Biconcave, enucleated discs – 7-8µm in diameter o Contain heme (an endogenous pigment) o Biconcave shape increases surface area 20-30% o High surface area : volume ratio • No MB-bound organelles • Energy source is glucose o 90% from anaerobic metabolism – degraded to lactate o 10% from HMP shunt

Function = O2 & CO2 transport o Oxyhemoglobin = hemoglobin molecule + O2 o Carbaminohemoglobin = hemoglobin + CO2 (~70% of CO2 is transported as bicarbonate ions)  Remember Carboxyhemoglobin is CO • RBC MB contains chloride-bicarbonate antiport – allows transport of CO2 to lungs for elimination • Hematocrit = proportion of erythrocytes in a blood sample o 46%, for males, 40% for females • Formed via erythropoiesis – stimulated by erythropoietin produced in kidney o In erythropoiesis, the cytoplasmic acidophilia increases (Duh, they become more red – ) o In erythropoiesis, cells trend toward:  A progressively smaller size  A progressive loss of organelles  A progressive increase in cytoplasmic Hemoglobin concentration • Average life span = 120 days o Normoblast is a developmental stage of the erythrocyte (not monocyte, lymphocyte, or eosinophil) • Shrink and crenate in hypertonic solution • Become ghost cells in hypotonic solution • Erythrocytosis = polycythemia = ↑ # of RBCs • Anisocytosis = varying sizes • Poikilocytosis = varying shapes 2) Platelets – 250-400k/mm3 • Cytoplasmic fragments of cells that promote clotting (as part of hemostasis) o Thrombopoietin stimulates megakaryocytes to give rise to platelets • Minute, irregularly shaped, disk-like cytoplasmic bodies found in blood plasma • No nucleus, DNA or hemoglobin • Life span is 5-9 days – removed in spleen & liver • Stop blood loss by forming a platelet plug • Contain secretory vesicles (granules), which release ADP & others chemicals when platelets adhere to collagen o Induces changes that make platelet surface sticky o Additional platelets adhere to original platelets to form plug • Thromboxane A directly promotes platelet Aggregation o Where PGI “inhibits Platelet grouping” 3) Leukocytes – 5-10k/mm3 • Neutrophils – 60-70% [of leukocytes] in a differential blood count o More recent #s say 40-75% o Lobed nucleus, fine granules o Large, spherical azuriphilic 1° granules (lysosomes)  Contain hydrolytic enzymes, lysosyme, myeloperoxidase, & lactoferrin o Function = phagocytosis (they love to ingest bacteria) o Nucleus becomes more hyperchromatic during the development in the red bone marrow o Neutrophils w/ > 5 lobes are called “hypersegmented” • Lymphocytes – 20-30% (agranulocytes) o Round nucleus, little cytoplasm o Function = produce Ab, destroy specific target cells o T cells:  Differentiate in the thymus  Account for 70-80% of circulating lymphocytes  Produces cell-mediated immunity  Interact w/ specific antigen, become sensitized & differentiate into several types of daughter cells: • Helper T cell (CD4)—helps activate other T lymphocytes • Cytotoxic T cell (CD8)—combines w/ Ag on surface of foreign cell causing lysis & cytokine release • Suppressor T cell—suppresses activation of immune system – maintains hemostasis & tolerance to self • Memory T cell—remains inactive until 2nd exposure to same Ag – then reproduce to mount a faster reaction o Aka ‘delayed hypersensitivity T cell’ o B cells:  Differentiate in bone marrow  20-30% of circulating lymphocytes  Antibody immunity  Once activated by/sensitized to Ag→daughter cells that either make Ab/s or become memory cells  Memory B cells→plasma cells (after 2nd exposure to Ag) •

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 Can function as an APC via MHC Class II Plasma cells:  Differentiated from B-cells  Found mainly in bone marrow and CT; and sometimes blood  Off-center nucleus & clock-face chromatin distribution  Short 5-10 day life  Specific immunity • Aid in the immunologic defense of the body (NOT mast cells, neutrophils, giant cells) • Plasma cells (NOT T-cells or B-cells) produce most of the body’s Ab/s  Contain large amount of rough ER & well-developed Golgi apparatus (Same with Mucous secreting Goblets)  Are found in the inner medullary center of lymph nodes (aka Medullary Cords) • Monocytes – 2-6% (agranulocytes) o Kidney-shaped nucleus (Crescent Moon shaped) o Differentiates into macrophages in tissues o Function = phagocytosis • Eosinophils – 1-4% o Lobed nucleus, red or yellow granules o Function = may phagocytize Ab-Ag complexes o Contain histiminase, acid phosphatase, and aurosulfurnimase • Basophils – 0-1% o Obscured nucleus, purple granules o Function = release histamine, heparin, serotonin, & SRS-A (slow reacting substance of anaphylaxis) o Similar to mast cells w/ coarse cytoplasmic granules  Granules contain heparin (anticoagulant), histamine (vasodilator) and bradykinin, serotonin, & SRS-A (slow reacting substance of anaphylaxis)  Heparin can prevent blood coagulation & can speed the removal of fat particles from blood after a fatty meal Occur in most loose CT, especially along the path of BVs o NOTE: serum = blood plasma w/o fibrinogen o

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Bone marrow: o Produces WBCs, RBCs & platelets by hematopoiesis o Red marrow:  Cavities of cranial bone, vertebrae, ribs, sternum, & ends of long bones  Prior to birth, other areas produce blood elements: liver, spleen, lymph nodes  Hemacytoblasts (pluripotent stem cells): • So, the principal site of granulocytic hemopoiesis in the adult human is red bone marrow o Yellow marrow:  Found only in cancellous (spongy) tissue of certain bones: • Flat skull bones, ribs, sternum, vertebrae, portions of ossa coxae & proximal epiphyses of humerus & femur  Minor location of fat storage

ARTERIES  Blood vessel walls:  Tunica intima  Innermost layer  Consists of simple squamous epithelium (endothelium) and a

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thin CT basement MB  ONLY layer present in all vessels  In atherscletotic pt, this is the layer involved in the hypertrophy Tunica Media  Middle Layer  Usually very thick in arteries (smooth muscle w/ some elastic fibers). In Lg arteries, elastic fibers are most prominent. In small arteries, smooth muscle is most prominent in this layer.  What keeps blood flowing during diastole  energy stored in elastic fibers of arteries Tunica Externa (Adventitia)  Outer layer of CT w/ elastic & collagenous fibers  The tunica adventitia of the medium sized artery has mostly what?  collagen and elastin

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In larger vessels, infiltrated w/ tiny BVs called vasa vasorum (vessels of the vessels) that nourish external tissues of BV wall

 Arteries  Highest BP found here  Greatest drop/change/gradient in BP is from the arteries to the arterioles  There are more elastic membranes in a large artery than there are in a medium-sized artery  Arterioles  Very small diameter (70% of blood is found in the venous system at any one time  Valves in veins of arms & legs prevent backflow  Veins & arteries have pulse present, none in capillaries  Veins have larger tunica adventitia when compared to arteries  Artery: Media is thickest layer  Vein: Adventitia is thickest layer  Caps→Venules→Veins→Vena Cava  Venules have very thin tunica adventitia  Larger veins have thicker tunica adventitia  Drainage from Brain to Right Atrium  Superficial region of head & neck drains into External Jugular Vein (EJV)  EJV empties into the Subclavian Vein (coming from the Axillary Vein of the shoulder)  Subclavian Vein joins the IJV (coming from the Sigmoid Sinus of the brain)  IJV & SCV join to form the Left Brachiocephalic Vein  The Left Brachiocephalic Vein then receives the Vertebral Vein from the posterior portion of the head  Left Brachiocephalic Vein meets the Right Brachiocephalic Vein to form the Superior Vena Cava → Right Atrium  Veins (Individual Facts)  Superior Vena Cava (SVC):  Union of two Brachiocephalic Veins, has no valves, blood from head, neck, upper limbs, & chest; empties into Right Atrium  Inferior Vena Cava (IVC):  Larger than SVC  Guarded by a rudimentary non-functioning valve  When IVC gets slowly occluded, there are collateral routes through BOTH epigastric veins AND the total azygos system  Brachiocephalic Veins:  Formed at the base of the neck from the joining of the IJV & SCV  Present on both sides of the neck  The R & L Brachiocephalics meet in the superior mediastinum to form SVC  Azygos vein (right side) – joins the posterior aspect of the SVC just before it pierces the pericardium (that’s why its collateral circulation)  Infection of lower lip would first enter bloodstream at the Brachiocephalic Vein  Infection spreading via lymphatic system from the vermiform appendix first enters the bloodstream at the brachiocephalic vein.  Internal jugular vein (IJV):  Begins at jugular foramen as a continuation of the Sigmoid Sinus  Descends in the carotid sheath  Descends behind sternoclavicular joint w/ SCV to form Brachiocephalic Vein  Drain the venous sinuses of the skull  External jugular (EJV):  Drains the skin, parotid, & muscles of the face & neck  Formed by union of the Posterior Auricular Vein & the posterior branch of the Retromandibular Vein  Crosses the SCM vertically, under the platysma, and ends in the SCV (DIFFERENT than Artery)  Subclavian Vein (SCV):  Continuation of the Axillary Vein at the inferior margin of the 1st rib • Passes medially to join the IJV to form Brachiocephalic Vein • Crosses 1st rib anterior to the anterior scalene muscle (Subclavian a. goes Posterior) ♦ So does the Phrenic  Subclavian tributaries are: • EJV on the left side at the angle of its junction w/ IJV • Lymphatics from the Thoracic Duct • On the right side it receives the Right Lymphatic Duct at the same location  Axillary Vein:  Begins at the lower border of the teres major muscle as the continuation of the Basilic Vein  Located in the Deltopectoral Triangle  (Think ABCs) Axillary Vein is really the union of the Cephalic (radial side) & the Basilic (medial side – formed after the Median Cubital Vein shoots off of the Cephalic Vein) • Brachial Vein—drains venous blood from deep antebrachial regions and brachial regions to Axillary Vein • Cephalic Vein—drains venous from radial side to the antebrachium and brachium into Axillary Vein

Superiorly the vein passes between the deltoid and the pectoralis major muscles and enters the deltopectoral triangle where it joins to be the axillary vein  Becomes the SCV as it ascends to the inferior margin of the 1st rib  Basilic + Cephalic = Axillary→Subclavian (receives EJV)…Subclavian + IJV (Jxn for thoracic duct = Brachiocephalic  Vertebral Vein:  Drains posterior portion of head  Then empties into the Left Brachiocephalic before it forms the Superior Vena Cava  Azygos Vein: (right side)  Drains posterior abdominal and thoracic body wall  Usually formed by union of the Right Ascending Lumbar & Right Subcostal Vein  Ascends through the aortic orifice of the diaphragm (A for A)  Lies in the posterior mediastinum & empties into the SVC at the junction of the 2 Brachiocephalic Veins  The Right Vagus nerve lies just posterior to the arch of the azygos • The Va-goose is most posterior  Azygos vein leaves an impression on the right lung as it arches over the root/hilum  Right Superior Intercostal Vein drains into Azygos vein. • NOTE: the 2nd, 3rd & 4th R posterior intercostal veins drain from the R superior intercostal vein into the azygos vein  Left Superior Intercostal Vein drains into the Left Brachiocephalic Vein at level of ????  Hemiazygos Vein: (left side)  Formed by union of the Left Ascending Lumbar Vein & Left Subcostal Vein  Empties into the Azygos Vein  Ascends on the left side of the vertebral body behind the thoracic aorta, receiving the lower four Posterior Intercostal Veins  Accessory Hemiazygos Vein:  Formed by union of 4th -8th Intercostal Veins  Empties into Azygos Vein, sometimes meets up with the Hemiazygos first then crosses and joins the azygos  Superficial Temporal Vein:  Drains the scalp & side of head  Descends anterior to the ear and plunges into the substances of the parotid gland  Maxillary Vein  Forms from the Pterygoid Plexus of Veins  Joins the Superficial Temporal Vein w/in the parotid gland to form the Retromandibular Vein  Retromandibular Vein: (Think Terminal Branches of Arterials)  Formed by union of Superficial Temporal & Maxillary vein w/in parotid  Divides at the angle of Mn into: • Anterior Branch – joins Facial Vein to form Common Facial Vein, which then drains into the IJV • Posterior Branch – joins Posterior Auricular Vein (occipital) from behind ear to form EJV  Veins of Cervical Triangle: Retromandibular Vein, EJV & IJV  Facial Vein  Begins as Angular Vein by the confluence of the Supraorbital and Supratrochlear Veins  Communicates w/ Superior Ophthalmic via the Supratrochlear and Supraorbital allowing infection from face to the Cranial Dural Sinus  Drains directly into the IJV or joins the Anterior Branch of the Retromandibular Vein to form Common Facial Vein which also enters IJV  The Facial Vein anastamoses w/ Retromandibular Vein below the border of the Mn & empties into the IJV, usually through the Common Facial Vein  Angular Vein • Continues at the lower border of the orbital margin into the Facial Vein • Receives the Infraorbital and the Deep Facial Veins ♦ Deep Facial Vein communicates between Facial Vein and the Pterygoid Plexus (which also becomes Max Vein) ♦ Superior Ophthalmic Vein is a communication between the Facial Vein & Cavernous Sinus  Deep Facial Vein  Communication between the Facial Vein & Pterygoid Plexus  Superior Ophthalmic Vein  Communication between the Facial Vein & Cavernous Sinus  Inferior Ophthalmic Vein  Divides into two terminal branches • One to the Pterygoid Plexus • One to the Superior Ophthalmic Vein to the Cavernous Sinus  Pterygoid Plexus of Veins:  The pterygoid plexus is in between the temporal and pterygoid muscles ♦

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The pterygoid plexus and its tributaries are the venous parallel of the maxillary artery – drains all correspondents to maxillary artery. Infection that spreads posterior to Mx sinus enters here Terminates posteriorly in the Maxillary Vein Terminates anteriorly in the Deep Facial Vein (drains into Facial Vein) The pterygoid plexus drains into the retromandibular vein  Retromandibular splits into Anterior and Posterior divisions: • Anterior – joins Facial Vein to form Common Facial Vein and then dumps into internal jugular vein • Posterior – receives the posterior auricular veins and forms the external jugular vein, which then drains directly into the subclavian vein Direct communications: - “DIMPsa”  Deep Facial vein  Infraorbital vein  Maxillary vein  Posterior Superior Alveolar vein • NOT Vertebral…Duh! Surrounds the maxillary artery occupying the infratemporal fossa associated w/ pterygoid muscles Receives veins that correspond to the maxillary artery

Dural Venous Sinuses. View is with the skull cap removed and the cranial cavity exposed. A. Sphenoparietal B. Intercavernous C. Sigmoid D. Occipital E. Confluence F. Basilar G. Transverse H. Superior Petrosal I. Inferior Petrosal J. Cavernous K. Superior Sagittal

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 The Cavernous Sinuses:  Paired, irregularly shaped Venous Dural Sinuses  Created by drainage of Superior & Inferior Ophthalmic Veins, the Cerebral Veins, & the Sphenoparietal Sinus  Located on either side of the sella turcica of sphenoid bone in middle cranial fossa  Empty by way of Superior Petrosal Sinuses into the Transverse Sinuses which become the Sigmoid Sinuses  The Sigmoid Sinuses then empty into the Jugular Foramen by becoming the IJV  These veins do not have valves and so can also drain anteriorly into Ophthalmic Vein Internal Carotid Artery and abducens (CN VI) nerve pass through the Cavernous Sinuses (CN VI is free-floating) All of the others are embedded in lateral wall of the Cavernous Sinuses:  Oculomotor (CN III), Trochlear nerve (CN IV), Ophthalmic nerve (CN V1), Maxillary nerve (CN V2) Think Caversnous s-EYE-nuses (III, IV, VI are eye movers, & V1/V2 are above & below the eye on the face) The Sinuses  Superior Sagittal • At the top of the falx cerebri • CSF flows into the arachnoid villi into the superior sagittal sinus  Inferior Sagittal • At the bottom of the falx cerebri  Straight sinus • When the great cerebral vein meets the inferior sagittal sinus, they form the straight sinus which takes them down to the Confluence  Occipital • In the falx cerebelli  Confluence of sinuses

• Where the Superior Sagittal, Straight, Occipital, and both Transverse Sinuses meet in the back Transverse sinus • The 2 lateral sinuses that connect the Confluence to the Sigmoid Sinuses  Sigmoid • Connects to the Internal Jugular Vein via the jugular foramen of the skull • Also collects the Superior Petrosal Vein  Cavernous sinuses • Anterior and Posterior intercavernous sinuses surround the Infundibular stalk of pituitary • Drain the valveless ophthalamic & paranasal sinuses – danger of infection  Sella turcica  Lies directly above the sphenoid sinuses  Middle cranial fossa  Diaphragma sellae  The tentorium cerebelli forms the roof of the posterior fossa Danger triangle of face:  Covers the nose and maxilla and goes up to the region of the eye  Superficial veins communicate w/ the Dural Sinuses  Facial Vein has no valves and backflow of infection can get into the sinuses via the Deep Facial Vein (via Pterygoid Plexus) and Superior Ophthalmic Vein (via Cavernous Sinus) Veins of the Skull:  Veins of the brain are Direct tributaries to the Dural Sinuses (Cerebral Sinuses, or the sinuses of dura mater)  Various venous channels located in the dura mater and lined w/ endothelium  Emissary Veins: (THINK you have to go THROUGH the checkpoint to get to the COMMISSARY on BASE (of skull) • Valveless, connect the dural sinuses w/ the veins of scalp • Differently worded: emissary veins connect the venous sinuses of the dura mater w/ the extracranial veins  Diploic Veins: • Lie in channels in the diploe of the skull & communicate w/ Dural Sinuses, the veins of the scalp, and Meningeal Vein • Lie w/in the bone of the calverium and join as tributaries to the Emissary Vein Portal Vein (aka: Hepatic Portal Vein):  Formed by the union of the Splenic and the Superior Mesenteric Veins  Tributaries are R & L Gastric Veins & the Cystic Vein  Passes:  Anterior to the epiploic foramen in the free edge of the lesser omentum • Epiploic foramen is bounded anteriorly by the free border of the lesser omentum • Greater peritoneal sac communicates with lesser peritoneal sac by means of the epiploic foramen  Posterior to the bile duct and the Proper Hepatic Artery  Ascends in front of IVC  Divides into R & L branches before entering liver  Carries 2x as much blood as the Hepatic Artery  Drains stomach, intestines, spleen, pancreas, and gallbladder  Drains into Hepatic Sinusoids, which then drains into the Center Vein  Here the blood travels through the hepatic portal system & makes it possible for the liver to perform many functions, (like remove substances from blood, metabolize, detox)  After leaving liver, blood travels through Hepatic Vein to IVC Splenic vein:  Drains spleen  Receives tributaries from:  Stomach = R & L Gastroepiploic Veins and R & L Gastric Veins  Pancreas = Pancreatic Vein  Gallbladder = Cystic Vein  Joins the Superior Mesenteric to form the Portal Vein 2 abdominal anastomeses  Superficial  Superficial epigastric to the Lateral thoracic (off of subclavian)  Deep  Inferior epigastric from the external iliac to the Internal thoracic Superior Mesenteric drains:  Small intestine, cecum, and ascending & transverse colon  Joins Splenic Vein behind the neck of the pancreas to form the Portal Vein Inferior Mesenteric:  Drains rectum, descending colon of the large intestine  Usually joins the Splenic Vein behind the neck of the pancreas 

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 Fetal vessels and their remnants:  One Q reads: Ligamentous remnants of the fetal circulatory system persisting in the adult include the ligamentum venosum, ligamentum arteriosum, ligamentum teres of the liver (not ligamentum nuchae or ligamentum teres of the uterus)  Umbilical Vein (1)→ Ligamentum teres (aka: “Round ligament of the liver”): (UV LighT)  Connects Placenta to liver, forms major portion of umbilical cord, nutrient-rich blood from placenta to fetus  Forms the round ligament of the liver after birth (ligamentum teres)  Umbilical Arteries (2)→Medial Umbilical Ligaments: (U A MULe)  Arise from Internal Iliac arteries associated w/ umbilical cord  Transports blood from fetus to placenta, becomes adult medial umbilical ligament  Allantois→Median Umbilical Ligament  Ductus Arteriosus→Ligmentum Arteriosum: (“Ductus”) (PDA – Pulm Art Duct ArtAorta)  Between pulmonary trunk (left pulmonary artery) & aortic arch to bypass pulmonary circuitry • R to L shunt, we don’t care about pulmonary circ. • Does not carry fully oxygenated blood  Closes shortly after birth, atrophies, & becomes the ligamentum arteriosum  Ductus Venosus→Ligamentum Venosum (LDI – Liver Ductus venosusInferior vena cava)  Only fetal vessel to carry O2-rich blood and nutrients. All others carry mixture of arterial and venous blood.  After Umbilical vein reaches the liver, then the Ductos venosus takes the blood to the IVC  Right Atrium  foramen ovale  Umblicial vein to the IVC (Just distal to where the bad blood was sent out in the iliac arteries)  Foramen Ovale→Fossa Ovalis: (AOA – Atrium foramen OvaleAtrium)  Opening between R & L atria to shunt blood passed the pulmonary circuitry, closes at birth and becomes the fossa ovalis, a depression in the interatrial septum  Notochord  Nucleus Pulposus  NOTE: The following are immediate changes that occur in the cardiovascular system at birth:  Closure of foramen ovale  Closure of the ductus venosus  Constriction of the ductus arteriosus  Constriction of the umbilical arteries  Not closure of the interventricular foramen  Since we’re thinking about the umbilical cord:  Contains 2 umbilical arteries – de-O2’d blood FROM fetus  Contains 1 umbilical vein – O2’d blood TO fetus (from placenta) -

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LYMPH SYSTEM Lymph o Transparent, usually slightly yellow, often opalescent liquid found in lymphatic vessels o Contains a liquid portion resembling plasma, as well as WBCs (mostly lymphocytes) & a few RBCs o Absorbed from tissue spaces by lymphatic capillaries o Flows through the filtering system (lymph nodes) o Is eventually returned to venous circulation by lymphatic vessels Functions of Lymphatic System: o 1) Collect & return tissue fluids back to bloodstream  Fluid entering lymph capillaries is called lymph • Fluid enters due to differing osmotic pressure across capillary MB  Lymph is returned to venous system via 1) thoracic duct & 2) right lymphatic duct  Lymphatic system depends on: • Skeletal muscle contraction, presence of valves in lymphatic vessels, breathing & gravity to move fluid  VS Veins • Walls of lymph vessels are thinner • Muscle layer is less developed o 2) Transport absorbed fats  Lacteals transport fat products in small intestines from GI into circulatory system  Lacteals are lymph capillaries w/in villi of small intestine o 3) Provide immunologic defense against disease-causing agents  Lymph filters through lymph nodes  Lymph nodes filter out microorganisms & foreign substances Basic framework of all lymphoid tissues (EXCEPT Thymus) is primarily reticular fibers and lesser amount of collagen fibers In the upper limb, the hallmark of lymph vessels is that they CONTAIN Valves –Sean you got clowned Bone marrow is part of lymph system

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Chief characteristic of lymphatic organ is presence of lymphocyte Lymph nodes: o Small, oval/round bodies of lymphatic tissue permeated by lymphatic channels o Contains both afferent & efferent vessels (spleen, thymus, tonsils do not have both)  Contains numerous afferent lymphatic channels (spleen, thymus, palatine/pharyngeal tonsils do not)  The spleen, thymus, palatine & pharyngeal tonsils do not have numerous afferent vessels entering them as do lymph nodes o Primary function – act as filters that remove & destroy Ag/s circulating in blood & lymph  Contain a lot of macrophages o Lymphoid tissue in nodes produces Ab/s & stores lymphocytes o Generally occur in clusters, particularly in armpits, groin, lower abdomen, & sides of neck o Each node is enclosed in a fibrous capsules w/ internal trabeculae (CT) supporting lymphoid tissue & lymph sinuses  Trabeculae are specialized bands of CT that divide the lymph node o Outer cortical region:  Contains separate masses of lymphoid tissue (called germinal centers, nodules) – source of lymphocytes • NOTE: The germinal center of a lymph nodule represents the area of proliferation of lymphocytes  Also contains subscapular & cortical sinuses  Outer cortex – B cells & nodules  Inner cortex – T cells & NO nodules o Inner medullary region:  Lymphoid tissue here is arranged in medullary cords – source of plasma cells  Also contains medullary sinuses Travel of lymph through nodes: o Afferent lymphatic vessels carry lymph into node – vessels enter on convex surface of the node  Lymph is cleansed by macrophages, lymphocytes & plasma cells as it circulates through cortical sinuses o Efferent lymphatic vessels carry filtered lymph through the concave hilus region into efferect collecting vessels o Collecting vessels converge into larger vessels – lymph trunks (five in the body)  There are fewer efferents than afferents o Lymph trunks empty into the thoracic duct or right lymphatic duct  Thoracic duct • Ascends between aorta and azygous vein • Drains most of the body • Empties into junction of the LEFT internal jugular & LEFT subclavian veinsf (which becomes the L brachiocephalic v.)  Right lymphatic duct • Drains right side of head & neck, right upper limb, & right side of thorax • Empties into junction of RIGHT internal jugular & RIGHT subclavain vein Deep cervical lymph nodes: o Eventually receive all lymph of head & neck o Form a chain along the internal jugular vein, from skull to root of neck o Efferent vessels join to form the jugular lymph trunk – then drain to thoracic duct or right lymphatic duct o Mandibular 3rd Molars initially??? – o Carcinoma of the larynx would most likely affect?  Deep cervical lymph nodes Parotid lymph nodes: o Strip of scalp above parotid salivary glands o Anterior wall of external auditory meatus o Lateral parts of eye lids & middle ear o **Drain into deep cervical lymph nodes Submandibular lymph nodes:

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o Lymph from most of the dental and periodontal tissues drains initially into the submandibular lymph nodes o Front of scalp o Nose & adjacent cheek o Upper & lower lips (except center part) o Drain the Oral Cavity o Mx & Mn teeth (except Mn incisors) (don’t get clowned by infraorbital lymph node for drainage of Mx teeth) o Anterior 2/3 of tongue (except the tip) o Floor of mouth & vestibule & gingiva o Angle of the mouth o **Drain into deep cervical lymph nodes Submental lymph nodes: o Tip of tongue o Anterior floor of mouth (beneath tip of the tongue) o Mn incisors & associated gingiva o Center part of lower lip & skin over chin  NOT Mn molars, upper lip, lateral portion of lower lip o **Drain into submandibular & deep cervical lymph nodes ***NOTE: The primary lymph nodes draining the mandible are the submandibular & submental nodes Thoracic duct: o Conveys lymph from lower limbs, pelvic & abdominal cavities, left side of thorax, & left side of head, neck & left arm o Begins below the abdomen as dilated sac – the cisterna chyli o Ascends through aortic opening in diaphragm, on the right side of the descending aorta o Empties into junction of the left internal jugular & left subclavian veins o Contains valves & ascends between the aorta & azygos vein in the thorax (Azy –goose and Thoracic DUCK touch) Right lymphatic duct: o Drains the right side of the head & neck, right upper limb, & right side of the thorax o Empties into junction of the right internal jugular & right subclavian veins Spleen: (STUDY MORE!!!) o Largest single mass of lymphoid tissue in body o Ovoid organ ~size of a fist o Develops from mesenchymal cells of the mesentery attached to primitive stomach – Not from the gut. o Found in closest relation to the inferior surface of the diaphragm o Lies in left hypochondrium of abdominal cavity between stomach & diaphragm o Important blood reservoir o Filters blood ONLY (No afferent lymphatics) o Phagocytosis of undesirable blood particles o Manufactures mononuclear leukocytes o White pulp  One card says: Contains lymphatic nodules & lymphocytes, like a lymph node  Another card: Contains compact masses of lymphocytes surrounding branches of the splenic artery o Red pulp  Consists of a network of blood-filled sinusoids, along w/ lymphocytes, macrophages, plasma cells, monocytes & RBCs  Contains: splenic cords, numerous erythrocytes and blood vascular sinusoids o PALS is the center zone of the spleen, surrounding the Central arteriole  *USMLE says: “T cells are found in the PALS & the red pulp. B cells are found in follicles w/in the white pulp.” • The B cells in the white pulp are analogous with the B cell outer cortical germinal centers in the lymph node o Site of erythropoiesis in fetus & infant – not in adults  Fetal erythropoiesis takes place in the Yolk sac, Liver, Spleen, Bone marrow (Young Liver Synthesizes Blood) o Travel of blood through spleen:  Enters at the hilum through the splenic artery  Drained by the splenic vein – joins lesser mesenteric vein to form hepatic portal vein to the liver w/ greater mesenteric vein  *Nerves to spleen accompany the splenic artery & are derived from the celiac plexus Thymus: o Bilobed lymphoid organ located in the superior mediastinum – has no lymphatics o Main function – to develop immature T-cells into immunocompetent T-cells  Tests new T cells for ability to recognize self-MHC molecules & self-epitopes – these T cells are destroyed o Thymus large in newborns, grows until puberty & then regresses in adults o In the adult thymus – blood supply is isolated from parenchyma – blood thymus barrier—supply is MOST isolated from the parenchyma of the thymus (more than the other options: spleen, lymph node, Peyer’s patch, pharyngeal tonsil) o In the child’s thymus – blood supply is NOT isolated from parenchyma o Hassel’s corpuscle are characteristic of the thymus histologically Pharyngeal tonsils: Tonsils mainly produce SIgA.

When inflamed, they are called adenoids Collection of lymphatic tissue located in posterior wall & roof of nasopharynx No lymph, sinuses or crypts Surrounded partly by CT & partly by epithelium, which forms deep infoldings (which aren’t crypts??) Characteristically covered by ciliated pseudostratified columnar  This is the distinguishing feature histologically from the palatine tonsils Palatine tonsils: o Two masses of lymphoid tissue – one mass on each side of oropharynx o Reach maximum size during childhood & diminish considerably after puberty o Contain many crypts & lymphoid follicles – no sinuses  Think Crypts are in between your Arch CAVES o Surrounded partly by CT and epithelium o Found between palatoglossus and palatopharygeus Lingual tonsils: o Found on posterior portion of dorsum of tongue o Smaller & more numerous – each has single crypt Peyer’s Patches: o Follicular-associated epithelium  Enterocytes & M cells o Germinal center  IgA positive B cells, CD4 T cells & APCs o “Intestinal tonsils”, similar in structure & function to tonsils o Located in the lamina propria & submucosa of the ileum o Destroy bacteria o No Goblet cells o USMLE: M cells take up Ag. Stimulated B cells leave Peyer’s patch & travel thru lymph & blood to lamina propria of intestine, where they differentiate into IgA-secreting plasma cells. The IgA is transported across the epithelium to deal w/ intraluminal Ag Peyer’s patches & tonsils considered subepithelial & nonencapsulated lymphoid tissue (not thymus, lymph nodes) Lymph from lungs, bronchi, and trachea drain into the mediastinal lymph nodes The spleen, thymus, & lymph nodes are similar in that they all contain lymphocytes o Not all three filter blood, have a medulla and a cortex, serve as filters for tissue fluid, have afferent & efferent lymphatic vessels o o o o o

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BONE Function of bone: o Support o Protection o Body movement o Hemopoiesis o Mineral storage  Inorganic bone matrix is composed primarily of minerals Ca & P • Give bone its rigidity & account for ~2/3 of its weight  95% of calcium & 90% of phosphorous in body is deposited in bone/teeth  In mineralization of bone – inorganic material increases, water content decreases, but little change in collagen • Different than enamel o Not fat storage Nutrition of bone reaches cells of compact bone via caniliculi, capillaries, & Volkmann’s canals (not osseous matrix or lamellae) Bone formation: o 1st evidence of bone ossification – 8th week of prenatal development o Endochondral ossification: (ENDO – think long bones, condyles Long like FILES)  Most bones are endochondral derived • Begins as a hyaline cartilage model • Know Fxn of Hyaline Cartilage in bone growth • Calcified cartilage is replace by bone (don’t get clowned: hyaline cartilage is not “transformed” into bone) • Bone replaces cartilage – osteocytes replace chondrocytes  Short & long bones (bones of extremities & weight bearing bones)  Mandibular condyles  The list includes ethmoid, sphenoid, & temporal bones  Cranial Base  portions of the occipital, sphenoid, temporal, and ethmoid o Intramembranous:  Bone formed directly – no cartilage precursor  Takes place w/in MBs of CT

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Flat bones of skull (cranial vault) & face (e.g., nasal bone), & clavicle Mandible (except condyles), Maxilla • In ORTHO tx, the type of new alveolar bone formation is intramembranous  Contributes to growth of short bones & thickening of long bones  Involves transformation of osteoblasts to osteocytes o Once formed, bone grows by appositional growth o A disturbance in cartilage formation in a fetus results in deformities of the axial skeleton and the base of the skull Bones grow NOT formed by o Appositional Cells of bone formation & resorption: o Osteoblasts:  Synthesize collagenous fibers, bone matrix & promote mineralization during ossification  Become trapped in their own matrix & develop into osteocytes  Derived from mesenchyme (fibroblasts)  Have high RNA content & stain intensely with basic dyes (blue) o Osteoclasts:  Large, multinucleated Giant Cells containing lysosomes & phagocytic vacuoles • Reversal Lines: o Seen on the Cribiform plate (aka alveolar bone proper) of the alveolar process o Indicates cessation of osteoclastic activity  Originates from Mononuclear-phagocyte family (MONOCYTE)  Form Howship’s Lacunae o Osteoid:  Newly formed organic bone matrix that has not undergone calcification  Differs from bone in that it has no mineralized matrix o Osteocytes:  Maintain the bone tissue Bone properties: o Hard – due to calcification of extracellular matrix o Elastic – due to presence of organic fibers o Strong – due to collagenous fibrils Bone components: o Diaphysis  Cylindrical shaft of durable compact bone o Epiphysis  Caps diaphysis  Location of secondary ossification center  Spongy bone surrounded by compact bone  Contains red bone marrow  Erythropoiesis takes place mainly in the epiphysis says Sean o Epiphyseal plate  Between epiphysis & diaphysis  Region of mitotic activity – responsible for elongation of bone o Medullary cavity  Centrally positioned space w/in diaphysis  Contains fatty yellow bone marrow (everywhere else)  NOTE: Red marrow = Blood cell formation • Cranial, vertebrate, ribs, sternum, epiphysis of long bones o Nutrient foramen  Opening into diaphysis  Provides site for nutrient vessels to enter/exit medullary cavity o Articular cartilage  Hyaline cartilage caps of each epiphysis  Facilitates joint movement o Endosteum  Lines medullary cavity  Consists of supportive dense regular CT o Periosteum  Dense regular CT covering surface of bone  Site for ligament & tendon-muscle attachment  Responsible for diametric bone growth  Has an outer fibrous layer and an inner osteogenic layer

Compact bone (Lamellar)  Hard, outer layer of bone tissue  Covered by periosteum  Serves for muscle attachment  Provides protection & gives durable strength to bone • The component of bone tissue that gives a bone tensile strength is the collagenous fibrils of matrix  Consists of: • Matrix of compact bone is collagen plus salts of calcium & phosphorus • Osteocytes – bone cells • Osteon – a cylinder of compact bone composed of concentric lamellae (HENCE, lamellar or compact bone) o The oldest lamella of the osteon is the most central lamella o Osteon canals are oriented parallel to the predominant direction of force – like when you stand on an aluminum can • Lacunae – depressions in the matrix where an osteocyte is located • Lamellae – circular layers of osteocytes located in lacunae • Canaliculi – processes connecting lacunae – each canaliculus resembles a miniature canal • Haversian canal – central canal around which concentric lamellae are located o Contains BVs & nerves that serve the osteocytes o Exchange of substances between central canals & osteocytes occurs along canaliculi • Haversian system = Haversian canal + surrounding structures o Repeating system is found in compact bone of diaphyses of long bones • Volkmann’s canal = connects 2 Harversian canals o Cancellous (spongy or trabecular)  Porous, highly vascular, inner layer of bone tissue – branching network of trabeculae  Makes bone lighter & provides spaces for marrow  Seen as spicules or trabeculae o Immature bone (woven bone, nonlamellar bone, or bundle bone)  Laid down fast  Bundle bone receives the Sharpey’s fibers in the alveolar bone proper Surface features of bone: o Fissure  Sharp, narrow, cleft-like opening (groove) between parts of a bone that allows passage of BVs & nerves o Sulcus  Shallow, wide groove on bone surface that allows passage of BVs, nerves, tendons  A shallower & less abrupt cleft/groove than a fissure o Incisure (notch)  Deep indentation on the border of a bone o Fovea  Small, very shallow depression o Fossa  Shallow depression – may or may not be an articulationg surface (e.g., glenoid fossa & subscapular fossa, respectively) o Foramen  Opening through which BVs, nerves, or ligaments pass o Meatus (canal)  Tube-like passage running through a bone o Process  Bone projection that serves for attachment of other structures o Epicondyle  Projection or swelling on a condyle o Spine  Sharp, slender projecting process o Tubercle  Small, rounded process o Tuberosity  Large, rounded, roughened process o Trochanter  Large blunt projection for muscle attachments on femur o

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Crest  Prominent elevated right or border of a bone o Linea (line)  Small crest, usually somewhat straighter than a crest o Ramus  Major branch or division of the main body of a bone o Neck  Slight narrowing of the body of bone that supports the head o Lamina  Very thin layer of bone Unpaired bones – ethmoid, frontal, occipital, & sphenoid Ethmoid bone: o Sieve-like bone at base of skull, behind bridge of nose o Straddles mid-sagittal plane & aids to connect the cranial skeleton to the facial skeleton o Each sinus divided into anterior, middle & posterior air ethmoidal cells o Horizontal plate (cribriform plate)  Perforated (olfactory foramina) on either side of crista galli for passage of olfactory nerve bundles  Crista galli – sharp, upward, midline projection for attachment of falx cerebri o Lateral masses (right & left)  Project downward from horizontal plate  Contain ethmoid sinuses & lamina orbitalis (lamina papyracea – located in the orbital medial wall) • The thinnest portion of the orbit is the Medial wall • The roof of the orbit is made from the Frontal bone  Superior & middle conchae are curved plates of bone that form the medial surfaces of the lateral masses o Perpendicular plate  Downward projection from midline on the undersurface of horizontal plate  Forms upper portion of the nasal septum Sphenoid bone: o Single bone that runs through the mid-sagittal plane o Aids in connecting cranial skeleton to facial skeleton o Consists of a hollow body & 3 pairs of projections:  Hollow body • Contains the sella turcica (houses pituitary gland) & sphenoid sinuses  Greater wing forms lateral wall of orbit & roof of the infratemporal fossa • Foramina in greater wing provide access to both pterygopalatine & infratemporal fossa o Foramen rotundum – transmits maxillary nerve V2 . o Foramen ovale – transmits V3 and lesser petrosal nerve. o Foramen spinosum – transmits middle meningeal vessels & nerves to tissue covering brain  Lesser wing helps to form superior orbital fissure & roof of orbit • Contains optic canal (optic foramen) & ophthalmic artery  Superior Orbital Fissure • Located between greater and lesser wings of the sphenoid o Left & right pterygoid processes –  Project downward from near junction of each of the greater wings w/in body of sphenoid bone  Run along posterior portion of nasal passage  Each proccess consists of a medial & lateral pterygoid plate • Lateral pterygoid plate o Provides origin for both lateral & medial pterygoid muscles  Medial pterygoid originates from medial surface  Inferior head of lateral pterygoid originates from the lateral surface o ***Forms medial wall of infratemporal fossa • Medial pterygoid plate o Forms posterior limit of lateral wall of nasal cavity o Ends inferiorly as the hamulus (haMElus) for Medial  Hamulus = small, slender hook acting as a pulley for tensor veli palatine tendon (from vertical to horizontal)  What is located directly behind Mx 3rd Molar??  Hamular notch, or Mx tuberosity – It’s gotta be! TMJ components: o Mandibular fossa  Oval depression in inferior surface of base of zygomatic process of the temporal bone  Articulates w/ condyle of Mn to form TMJ o Articular eminence  Rounded bar of bone forming the anterior part of the Mn fossa o

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 Posterior slope of eminence is lined by fibrous CT TMJ cavity  Divided into upper & lower compartment by articular disc • Upper – disc glides forward on articular tubercle - translation • Lower – condyle rotates beneath the disc like a hinge – hinge action Alveolar bone: o Exists only to support teeth – if tooth never erupts, it never forms – if tooth is extracted, alveolus resorbs o In children, it increases in height & length to accommodate developing dentition o Position of tooth, not the functional load placed on it, determines the shape of the alveolar ridge o Alternate loosening and tightening of primary tooth about to shed is from alternate resorption and apposition of cementum and bone o The primary mineral component of alveolar bone in the periodontium is Hydroxyapatite Mandibular condyles: o Provides space for erupting molars o Major site of growth  Soft tissue development carries the Mn forward & downward  Condylar growth fills in the resultant space to maintain contact w/ the base of the skull o Long axes of Mn condyles intersect at foramen magnum, which indicates that axes are directed posteromedially o Growth at the mandibular condyles provides the space between the jaws into which the teeth erupt Hard palate: o Anterior 2/3 formed by palatine processes of maxilla o Posterior 1/3 by the horizontal plates of palatine bones o The portion of hard palate located directly posterior to the Mx central is derived from the medial nasal processes o Forms the roof of the oral caviy & floor of nasal cavity  If you over-implanted Teeth #7–10, you would penetrate the nasal cavity o Covered w/ a mucous MB – beneath these are palatal salivary glands o Submucosa of anterolateral is characterized by adipose tissue, where posterolateral contains nests of mucous salivary glands Roof of the oral cavity formed by the maxilla & the palatine bones; specifically the palatine processes of the maxilla & horizontal plates of the palatine bones. Same as the floor of the nasal cavity Soft palate: o Posterior to & continuous w/ hard palate o Contains  Lamina propia of loose fibrous CT  Tough fibrous CT sheet – the palatal aponeurosis  Salivary acini deep to the mucous membrane  Shallow, blunt rete pegs o Posteriorly, soft palate is suspended in the oropharynx ends in the midline uvula o Most palatal muscles receive innervation from pharygeal nerve plexus o Motor branchers of CN V3 to tensor mucles of palate o Sensory innervation provided by CN V2 Nasal cavity: o Bridge of nose is formed by two nasal bones o Lateral walls – formed by superior, middle, & inferior conchae o Bony floor – formed by palatine process of Mx & horizontal plate of palatine bone o Roof – formed by nasal, frontal, body of sphenoid & cribiform plate of ethmoid o Medial wall or nasal septum – formed by the perpendicular plate of ethmoid bone, vomer bone, & septal cartilage o The rest of the framework for bone consists of several cartilage plates  Specifically, the lateral nasal cartilage and greater & lesser ala cartilage  These are held together by fibrous CT o Opens on face through nares o Communicates w/ nasopharynx through choanae (posterior openings of nasal cavity to nasopharynx) o Nasal conchae:  Three pairs of scroll-like delicate shelves or projections, which hang into nasal cavity from lateral walls  Increase surface area w/in nasal cavity & expose the olfactory nerve to inhaled odors  Superior & middle conchae – part of ethmoid bone  Inferior conchae – separate bone (aka inferior turbinates) o Meatus of the Conchae: Plate 525 (Clemente)  Space below & lateral to each concha  Superior meatus • Receives openings of the posterior ethmoidal sinuses  Middle meatus o

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Receives the openings of: 4 things: (FAMM) o Frontal sinus – drains into infundibulum of middle meatus o Middle ethmoidal sinuses – drain onto ethmoidal bulla (rounded prominence on lateral wall of middle meatus) o Anterior ethmoidal & maxillary sinuses – drain into middle meatus via the hiatus semilunaris  Hiatus semiluminares – groove on lateral wall continuous w/ the infundibulum  NOTE: the maxillary sinus must drain upwards against gravity – makes maxillary sinus infections hard to treat  Inferior meatus: • Receives the opening of nasolacrimal duct – drains lacrimal fluid from eye surface of into meatus for evaporation Cranial fossae: o Anterior cranial fossa  Formed by frontal & ethmoid bones. (Lesser wings of sphenoid bone too – ECA 2nd ed. pps 504-5)  Contains: • Frontal lobes of cerebrum • Cribriform plate • Foramen cecum (contains emissary vein in fetal life) • Crista galli o Middle cranial fossa  Formed by sphenoid, temporal, & parietal bones  Contains: • Temporal lobes of cerebrum • Hypophysis cerebri (pituitary gland) • Optic & carotid canal (ECA puts optic in the anterior fossa. Clemente and BRS list them here…you decide.) • Superior orbital fissure • Trigeminal impression for trigeminal ganglion • Separates the middle ear cavity & sphenoid sinus • Which foramen is not in the middle cranial fossa  Jugular o Posterior cranial fossa  Formed by occipital & temporal bones  Contains: • Occipital lobes • Cerebellum, pons, & medulla oblongata • Internal auditory meatus • Jugular, condyloid, & mastoid foramen • Foramen magnum • Hypoglossal canal o Petrous portion of the temporal bone:  Forms the floor of the middle cranial fossa  Separates the middle cranial fossa from the posterior cranial fossa Zygomatic bone o NOT part of the calvarium, because it comes from the 1st Branchial arch o Aka cheekbone, malar bone or zygoma o Forms prominence of cheek & part of the lateral wall & floor of the orbital cavity o NOT part of the calvarium (Temporal, Occipital, Parietal, Frontal all are) o Anteriorly – articulates w/ maxilla o Posteriorly – articulates w/ zygomatic process of temporal bone to form the zygomatic arch Temporal fossa o Shallow depression on side of cranium bounded by temporal lines o Terminating below level of zygomatic arch o Area above zygomatic arch, filled w/ temporalis muscle o Lower margin is masseter muscle Infratemporal fossa o Communicates w/ pterygopalatine fossa via pterygomaxillary fissure (IN, UP, BACK – Just like PSA block) o Other openings communicating w/ the infratemporal fossa: foramen ovale, foramen spinosum (not foramen rotundum) o Lies posterior to maxilla, between pharynx & ramus of mandible, below infratemporal crest of greater wing of sphenoid bone o Boundaries of Infratemporal fossa:  Anterior wall – posterior surface of maxilla  Posterior wall – tympanic part & styloid process of temporal bone  Medial wall – lateral pterygoid plate of the sphenoid bone  Lateral wall – ramus of the mandible  Roof – infratemporal surface of greater wing of sphenoid bone • Contains foramen ovale – transmits V3 •

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 Floor – point where medial pterygoid muscle inserts into medial aspect of the Mn near the angle CONTENTS of infratemporal fossa: lots of Qs on this stuff  See 1999Q04 – I don’t like this one  Temporalis muscle (lower portion) • Temporalis muscle passes medial to the zygomatic arch & inserts into coronoid process  Medial & lateral pterygoid muscles • Between them runs the: o IA nerve and artery o Lingual nerve  NOT the nerve to the masseter  Maxillary artery & most branches (including middle meningeal artery) • MAJOR artery of the infratemporal fossa  Pterygoid plexus of veins  Mandibular nerve & branches – including lingual nerve  Chorda tympani  Otic ganglion (PS ganglion associated w/ glossopharyngeal nerve)  Sphenomandibular ligament o In a fractured condyle, muscular contractions may result in displacement of the condyle into the infratemporal fossa *Temporal & infratemporal fossae communicate w/ each other deep to zygomatic arch Infratemporal crest of greater wing of sphenoid bone o Separates the temporal fossa from the infratemporal fossa below it Pterygopalatine fossa (Think Sphenopalatine Fossa) o Communicates laterally w/ infratemporal fossa by way of pterygopalatine fissure o Formed by the sphenoid, palatine, and maxillary bones (not temporal) o Pterygopalatine ganglion:  Lies in the pterygopalatine fossa just below CN V2  Receives preG PS fibers from facial nerve by way of greater petrosal nerve  Also receives PostG Sympathetic fibers via the deep petrosal  Sends postG PS fibers to lacrimal gland & glands in palate & nose (NOT to parotid gland) o CN V2 & pterygopalatine portion of maxillary artery pass through the fossa Pterygopalatine fissure – communicates: o 1) Medially – w/ nasal cavity through sphenopalatine foramen  The Sphenopalatine formaen connets the pterygopalatine fossa with the nasal cavity o 2) Posteriorly – through pterygoid canal o 3) Posteriorly – w/ the cranial cavity through the foramen rotundum o 4) Posteriorly – w/ the pharynx through the pharyngeal canal o 5) Anteriorly – w/ orbit through the inferior orbital fissure o 6) Inferiorly w/ the Greater Palatine canal to the mouth  NO communication with Facial Canal Chest o Ribs  True 1-7  False 8-12 • Floating 11-12  Articulate with the spine at the superior articular process of same number and inferior facet for one number lower (higher on the spine) in a synovial joint and are surrounded by a radiate ligament • When the arched shaft of the ribs is elevated, transverse diameter of the pleural cavity is increased o Sternum  Sternal angle • The bottom of the sternal “shield” • Used to locate 2nd rib • Level of the branching of the trachea (where it passes behind the aortic arch) • Same plane as T5  Body of sternum articulates directly w/ manubrium & xiphoid process (not clavicle, 1st rib, 11th rib) Hip bone o Formed by fusion of ileum, ischium, pubis o Articulates w/ the sacrum at sacroiliac joint to form pelvic girdle o Two hip bones articulate w/ one another anteriorly at the symphsysis pubis o Ilium:  Upper flattened part of hipbone  Iliac crest – ends in front at anterior superior iliac spine & behind at posterior superior ilac spine  Greater sciatic notch – a large notch call o

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Ischium:  L-shaped w/ upper thicker part (body) & lower thinner part (ramus)  Bears weight of body when person is upright & seated  Ischial spine & ischial tuberosity  Obturator foramen – formed by ramus & pubis Pubis:  Body, superior ramus, & inferior ramus  Bodies of the two pubic bones articulate in the midline at symphysis pubis  Medial to symphysis is pubic tubercle  Inguinal ligament connects the pubic tubercle to anterior superior iliac spine Acetabulum:  Cup-shaped cavity on lateral side of hip bone  Receives the head of femur  Formed superiorly by ilium, posteroinferiorly by ischium & anteromedially by pubis

JOINTS Three main classes of joints (articulations): o Synarthroses:  Immovable joints (fibrous joints) – EX: sutures  In a newborn, intervals between bones in the middle of the cranial base is Hyaline cartilage (see spheno-occipital…↓15 lines) o Diarthroses:  Freely movable joints (synovial joints)  Aneural & avascular  Covered in hyaline cartilage or fibrocartilage (TMJ) o Amphiarthroses:  Slightly movable articulations in which the contiguous bony surfaces are either connected by broad, flattened disks of fibrocartilage or are united by interosseous ligaments (cartilaginous joints) – EX: pubic symphysis, vertebrates Joints can also be calssified based on the associated CT type: o Fibrous—joined by fibrous CT  1) Sutures  2) Syndesmoses – between radius & ulna  3) Gomphosis – tooth socket o Cartilaginous—joined by fibrocartilage or hyaline cartilage  1) Synchondroses – epiphyseal plates w/in long bones. Permit no movement but the growth within bone. • NOTE: The spheno-occipital synchondrosis in the midline of the cranial base of a newborn consists of hyaline cartilage  2) Symphysis – mental symphsis. Symphysies are joined by a plate of fibrocartilage and are slightly movable jts. Pubic symphysis and intervertebral discs are example. o *Synovial—joint capsule containg a synovial MB that secretes a synovial fluid  Lined with either Hyaline cartilage or fibrocartilage  Most joints are synovial – such as TMJ *Synovial joints: o Freely movable (diarthrodial) joints o Limited by one joint surface, ligaments, muscles, or tendons o Have 5 distinguishing features:  1) Articular cartilage: • Thin layer of hyaline cartilage that covers the smooth articular surfaces • Contains no BVs or nerves • NOTE: TMJ contains fibrocartilage – not hyaline cartilage  2) Synovial (joint) cavity: • Small fluid-filled space separation the ends of adjoining bones  3) Articular capsule: • Double-layered capsule o Outer layer – fibrous CT encloses the joint. o Inner layer – thin, vascular synovial MB (because it needs blood supply to produce synovia)  4) Synovial MB: • Secretes clear, thick fluid –Synovial fluid • Provides nutrition • Fills joint capsule & lubricates articular cartilage at the articulations  5) Supporting ligaments: • Capsular, extracapsular, & intracapsular ligaments • Maintain normal bone positioning

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o Some synovial joints have articular discs (i.e., TMJ & sternoclavicular joint) that divide the cavity into two separate cavities Bursa: o Fluid filled sac lined w/ a synovial MB o Function = reduce friction o May be located between tendon & bone to reduce friction during muscle contraction o Bursitis – inflammation of lining of a bursa o Subacromial bursa   Large synovial membrane which is adherent to undersurface of coracoacromial ligament, acromion, & deltoid laterally, & floor is adherent to rotator cuff & greater tuberosity;  It envelops proximal humerus, & facilitates gliding of proximal humerus under coracoacromial arch Atlanto-axial joint: o Allows for maximum rotational movement of head about its vertical axis o Synovial articulation between:  1) the inferior & articulating facets of the atlas (1st cervical vertebra)  2) the superior articulating facets of the axis (2nd cervical vertebra) o Movement of head in saying “NO” Atlanto-occipital joint: o Synovial articulation between:  1) the superior articulating facets of the atlas  2) the occipital condyles of the skull o Pemits rocking & nodding movement in saying “YES” MUSCLE

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Muscle fibers: o Sarcoplasm – cytoplasm of muscle cells  Contains many parallel, threadlike structures called myofibrils o Myofibrils  Large, multinucleated skeletal muscle cells  Each is comprised of smaller strands called myofilaments that contain contractile proteins: actin & myosin  An increase in #s of additional myofibrils causes muscle fibers to hypertrophy • This is caused by progressively greater numbers of both actin & myosin filaments in the myofibrils • The # of muscle fibers does not increase, the size of each fiber increases  I Band • Gets smaller with contraction • Only Actin o Z line  Separates adjacent sarcomeres  Where the T tubules lie  Desmin is also found at the Z lines • It aligns adjacent myofibrils in the myocyte, giving muscle its striated appearance  A Band (A for Alpha Male -- myosin, meaning it makes everyone come to it) • Doesn’t change size with contraction • Both actin, but Myosin dictates borders – this is because myosin (thick) is only present in the A Band o H zone (Think HOT zone, where the ACTIoN is coming)  Gets smaller with contraction  Only Myosin o M line o Sarcomere: (see figure)  Repeating contractile unit in the myofibril • Each sarcomere is enclosed between two Z lines (Think End of the alphabet)  Characterized by dark & light striations due to the arrangement of thick (myosin) & think (actin) filaments  Dark bands = A bands (anisotropic) • Contain myosin filaments throughout o In normal light microscopy of striated muscle, the dark portion of the striation is caused by the presence of myosin • Outer regions contain both actin & myosin • H band – central area of A band w/o actin/myosin overlap

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Light bands = I bands (isotropic) • Bisected by dark Z lines, where actin filaments of adjacent sarcomeres join o Sarcoplasmic reticulum:  Network of membranous channels, tubules & sacs in skeletal muscles  Analogous to endoplasmic reticulum of other cells  Extends throughout the sarcoplasm  The organelles that releases & sequesters/stores Ca2+ during muscle contraction & relaxation o Fibrous CT covering of muscle:  Epimysium: • The CT layer enveloping the entire skeletal muscle  Perimysium: • Continuation of the outer fascia, dividing the interior of the muscle into bundles of muscle cells • Fasciculus = bundle of cells surrounded by each perimysium  Endomysium: • The CT layer surrounding each muscle fiber • What immediately covers myofibrils? o Endomysium or Sarcolemma?????  The 3 levels of fascia are interconnected, allowing vessels & nerves to reach individual fibers & cells o Muscle-tendon junction  The union is made by a continuity of CT sheaths of the muscle with those of the tendon Motor unit o Def: alpha motor neuron + muscle fibers it innervates o Axon of motor unit is highly branched→one motor neuron innervates numerous muscle fibers o When a motor neuron transmits an impulse, all fibers it innervates contract simultaneously Muscle contraction o Tension develops because of interaction between actin & myosin filaments (see figure) o Actin filaments (thin myofilaments, 5-8 nm diameter); composed of:  Actin – globular actin (G-actin) molecules are arranged into double spherical chains called fibrous actin (F-actin)  *Tropomyosin – (Like ROPE-Omyosin)long, threadlike molecules, lie along surface of F-actin strands & physically cover actin binding sites during resting state  *Troponin – (LIKE TRIP, i.e. tripped the SWITCH) a small oval-shaped molecule attached to each tropomyosin o Myosin Filaments: (thick myofilaments, 12-18 nm diameter); composed of:  Light meromyosin (LMM) – makes up rod-like backbone of myosin filaments  Heavy meromyosin (HMM) – forms shorter globular lateral cross-bridges, which link to actin binding sites during contraction - Smooth muscle: o Responsible for involuntary movements of internal organs o Much smaller than skeletal muscle fibers o Composed of uninucleate, elongated, spindle-shaped cells (fusiform cells)  Do not possess regularly ordered myofibrils & are therefore NOT striated (myofibrils lack transverse striations)  Nuclei are found in the widest part of each fiber o Do NOT possess T-tubules & sarcoplasmic reticulum is poorly developed o Contraction process is slow & not subject to voluntary control Types of Smooth muscle  Single unit • Has numerous gap junctions (electrical synapses) between adjacent fibers • These fibers contract spontaneously • EX – muscular tunica of GI tract, uterus, ureters, & arterioles  Multi-unit • Lacks gap junctions • Individual fibers are autonomically innervated • EX: ciliary muscle & smooth muscle of iris, ductus deferens & arteries Skeletal muscle: o Responsible for voluntary body movement o

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Composed of bundles of very long, cylindrical, multinucleated cells  Possess regularly ordered myofibrils responsible for striated appearance (myofibrils have distinct transverse striations)  Striations consist primarily of actin & myosin proteins  Each fiber is innervated by an axon & motor neuron at a motor end plate o Enlarges with prolonged activity as result of increase in sarcoplasm and in the number of myofibrils of existing muscle fibers  Not from differentiation of myoblasts or mitotic division of muscle fibers o Nuclei are either slender ovoid or elongated & are situated peripherally  Only skeletal muscle has peripherally located nuclei o Contain transverse tubules (T-tubules -- at the Z line) & the sarcoplasmic reticulum is very well developed o Contraction is quick, forceful, & usually under voluntary control o Myofibrils (actin & myosin) are the contractile element o Triad consists of terminal cisternae and fingerlike invagination of sarcolemma Cardiac muscle fibers: o Make up thick, middle layer of heart known as the myocardium o Have larger T-tubules & less-developed sarcoplasmic reticulum as compared to skeletal fibers o Short, branched, & single or binucleated o Have more mitochondria between myofibrils; richer in myoglobin than most skeletal muscles o Contain large, oval, centrally placed nuclei o Characteristic feature – presence of intercalated discs  Strong, thin unions between fibers  Provide low resistance for current flow  Within the discs, desmosomes attach cells & gap junctions allow electrical impulses to spread from cell to cell o Can contract spontaneously w/o nerve stimulation o Respond to increased demand by increasing fiber size – known as compensatory hypertrophy o

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HEAD/NECK MUSCLES

Muscle SCM

Origin Sternum; clavicle

Digastric

Inferior border of mandible; mastoid groove

Mylohyoid (Know how to pick out of a diagram)

Mylohyoid line of mandible ** the mylohyoid ridge/line is located on the body of the mandible **The mylohyoid is the muscle responsible for displacing denture when extended too far inferiorly Styloid process of temporal bone Body and greater horn of hyoid bone

Stylohyoid Hyoglossus Sternohyoid Thyrohyoid

Manubrium Thyroid cartilage

Omohyoid

Superior border of scapula

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Muscles of Anterior Neck Insertion Action Mastoid process of Turns head to side; flexes temporal bone neck & head Hyoid bone (sling) Opens jaw; elevated hyoid bone Does move the mandible (opens) BUT is NOT a muscle of mastication Median raphe Elevates hyoid bone & floor of mouth NOTE: in the submental region, the mylohyoid is the 1st muscle to be penetrated from the skin NOT involved in mastication!! Body of the hyoid Elevates & retracts hyoid bone Lateral and dorsal tongue Raises the hyoid, retracts the tongue to the LATERAL FLOOR Body of hyoid Depresses hyoid Greater cornu of hyoid Depresses hyoid; bone elevates thyroid cart. Clavicle; body of hyoid Depresses hyoid bone

Only 3 muscles Depress the Hyoid  TOS, Thyrohyoid, Omohyoid, and Sternohyoid Superficial Muscles of the Neck??? o SCM o Platysma o Sternohyoid o Maybe Splenius Muscles??? Muscles of the Deep Neck

Innervation Accessory nerve Ant belly (V3) Post belly (VII)

Trigeminal V3

Facial N Hypoglossal n. Ansa cervicalis C1 via hypoglossal n. Ansa cervicalis

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Often called the lateral vertebral muscles Form a large portion of the floor of the posterior cervical triangle

Muscle Longus Capitus

Origin Anterior Tubercles of C3-C6 vertebral transverse processes

Longus Colli

Bodies of T1-T3, bodies of C4-7, and transverse processes of C3-C6

Scalenes

Anterior: Anterior tubercles of transverse processes of C3-C6 Middle: Posterior tubercles of the transverse processes of C2-C7 Posterior: Posterior tubercles of the transverse processes of C4-C6

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Muscles of Deep Neck Insertion Basilar portion of the occipital bone Anterior tubercle of the atlas (C1), bodies of C24, and transverse processes of C5-C6 Anterior: Scalene tubercle of 1st rib Middle: Superior surface of 1st rib Posterior: External border of 2nd rib

Action Flexes the neck **In front of the cervical vertebrae and are often called prevertebral ms. Flexes the neck (weakly), and slightly rotates and laterally bends the neck

Innervation C1-C3 ventral rami

Anterior and Middle: Elevate the 1st rib, when the 1st rib is fixed, they flex the neck forward and laterally rotate it to the opposite side

Anterior: C5-C7 ventral rami

Posterior: Raises the 2nd rib and flexes and slightly rotates the neck

C2-C6 ventral rami

Middle: C3-C8 ventral rami Posterior: C6-C8 ventral rami

Suboccipital Triangle o Deep in the triangle passes the vertebral artery and the Suboccipital nerve (aka dorsal ramus of C1) o Posterior Neck/Head Nerves  Greater occipital nerve (dorsal ramus of C2 spinal nerve)  Great auricular nerve (cervical plexus C2,3)  Lesser occipital nerve (cervical plexus C2,3)  Least occipital nerve (dorsal ramus of C3 spinal nerve)  Suboccipital nerve (aka dorsal ramus of C1)

Muscle Rectus Capitus Posterior Minor Rectus Capitus Posterior Major Obliquus Capitus Superior Obliquus Capitus Inferior

Muscles of Suboccipital Triangle Origin Insertion Action Arises from the tubercle Medial part of the Extends the head of the posterior arch of inferior nuchal line the atlas Arises from the spinous Lateral portion of the Extends head and rotates process of the axis inferior nuchal line it to the same side From the transverse Occipital bone between Extends the head and process of the atlas the superior and inferior bends it laterally nuchal lines Spinous process of the Inferior and dorsal Rotates the atlas, turning atlas portions of the transverse the face towards the process of the atlas same side

Innervation Suboccipital nerve (aka dorsal ramus of C1) Suboccipital nerve (aka dorsal ramus of C1) Suboccipital nerve (aka dorsal ramus of C1) Suboccipital nerve (aka dorsal ramus of C1)

Triangle Anterior Carotid (Superior) Submandibular (Digastric, Submaxillary) Submental Muscular (or inferior carotid) Omotracheal

Location & Contents of the Triangles of the Neck Boundaries SCM muscle, medial line of neck, inferior border of mandible SCM, posterior digastric, & omohyoid muscle Superior border is the posterior digastric Digastric muscle, inferior border of mandible ***NOTE: mylohyoid makes up the floor Digastric, hyoid bone (only unpaired triangle of neck) SCM & omohyoid muscles, midline of neck

Posterior (THINK Os) THE SCM divides the anterior and posterior triangles

SCM & trapezius muscles; clavicle

Occipital Omoclavicular (Subclavian)

SCM, trapezius, & omohyoid muscles SCM, & omohyoid muscles, clavicle

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Triangles o Anterior Triangle  Submental  Digastric  Carotid  Muscular o Posterior Triangle  Occipital and Omoclavicular o CN XII (Hypoglossal) travels from the Carotid triangle into the Mandibular triangle  Muscles that pass: • Medial scalene • Splenius capitis • Levator scapulae Hyoid Bone o Attached by muscles or ligaments to the mandible, clavicle, and tongue Sternocleidomastoid (SCM) o Origin

Contents Four lesser triangles, salivary glands, larynx, trachea, thyroid glands, various vessels & nerves. Carotid arteries, internal jugular vein, vagus nerve, CN XII (where the IJV originates from) Salivary glands, CN XII Muscles of the floor of the mouth, salivary glands & ducts Larynx, trachea, thyroid gland, carotid sheath Floor: Medial and Posterior Scalenes, Splenius capitus, Levator scapulae, Nerves & vessels, Anterior belly of Omohyoid (NOT sternohyoid) Cervical plexus, accessory nerve Brachial plexus, Subclavian artery

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2 heads of origin • Sternal head arises from the anterior surface of the manubrium of the sternum • Clavicular head arises from the superior surface of the medial third of the clavicle o ***Clavicle is first bone to calcify and is the most commonly broken o Insertion  To the lateral surface of the mastoid process and the lateral half of the superior nuchal line o Action  Tilts head to one side, flexes the neck, rotates the neck so the face points superiorly to the opposite side, both together flex the neck o Innervation  Spinal root of XI (and C2, C3) • Only Traps are also innervated by XI o Sternocleidomastoid separates the anterior & posterior triangles of the neck Platysma o Innervated by CN VII

Muscle of Mastication Origin Insertion Action Floor of the temporal bone Coronoid process of Mn Elevates & retracts Mn Zygomatic arch Lateral ramus of the Mn Elevates Mn to occlude teeth Medial surface of the Lateral Medial surface of angle of Mn Elevates Mn & moves Mn pterygoid plate & tuberosity of Mx & laterally pyramidal process of palatine bone Lateral pterygoid Superior head: Greater wing of the Superior head: Articular disc & capsule Opens, protrudes, & moves Mn sphenoid bone Inferior head: Condylar neck of Mn laterally Inferior head: Lateral surface of lateral pterygoid plate - Muscles of mastication o Two groups based on function:  Masseter, temporalis, medial pterygoid – elevate Mn to close mouth • In the temporalis, most elevation is from the anterior fibers, but the posterior fibers do contribute to elevation of Mn  Lateral pterygoid – depresses Mn to open mouth, translates jaw (side-to-side) & protrudes Mn  What about mylohyoid as an elevator of Mn – see 2000 Q01 • Kaplan says mylohyoid also depresses the Mn (bad Q!!!) o All receive blood supply from pterygoid portion of the Mx artery o Innervated by trigeminal nerve (V3) o Masseter & medial pterygoid form sling around angle of Mn  Superificial head of masseter inserts on lateral surface of angle & medial pterygoid inserts on medial surface of angle  Primary closing muscles – provide lateral stabilization of Mn  Both muscles exert similar forces upon Mn  Nerve to the masseter passes through the mandibular notch, BUT does not reach the muscle by passing through the mandibular foramen o Medial pterygoid muscle:  The lingual nerve, inferior alveolar nerve, & IA artery all pass between medial pterygoid & Mn ramus (not lingual artery) – I think the point of this Q is to test whether or not you know that the Lingual A. and N. take different paths.  If needle lies below mandibular foramen during IA block, it will pierce the Medial Pterygoid muscle  A diffuse swelling at the angle of the Mn & lateral neck of the condyle constrains the following muscle (NOT the medial pterygoids) • Digastric, mylohyoid, lateral pterygoid, geniohyoid o Lateral pterygoid muscle:  Condylar fracture or injury to lateral pterygoid results in deviation toward affected side  Damage to the articular disc of TMJ would result in paralysis of the lateral pterygoid muscle, which inserts on the articular disc, joint capsule, & neck of the Mn. The patient would be unable to open his/her mouth o Temporalis muscle:  Fan-shaped muscle originating from 1) the bony floor of the temporal fossa & 2) the deep surface of the temporal fascia  Inserts on the coronoid process of the mandible & the anterior border of the ramus of the mandible  Anterior & superior fibers elevate Mn; posterior fibers retract Mn (these fibers also contribute to elevation of Mn) • Primary function of the temporalis muscle is to elevate & retrude the Mn  Innervated by deep temporal nerves (branches of V3)  Arterial supply by the maxillary & superficial temporal arteries  Passes medially (downward & deep) to zygomatic arch as a thick tendon before inserting  Posterior fibers retract Mn & maintain resting position of closure of mouth Muscle Temporalis Masseter Medial pterygoid

In a double vertical fracture at the mental foramina, muscle action will cause the small fragment to move inferiorly & posteriorly. This probably has something to do with the Digastric muscle that attaches to the anterior mandible. Buccinator muscle: o Does not move the jaw o Innervated by CN VII o Complex origin:  Maxilla – along alveolar process superior to alveolar margin between 1st & 3rd molars  Mandible – along oblique line of Mn between 1st & 3rd molars  Pterygomaxillary ligament  Pterygomandibular raphe – thin, fibrous band running from the hamulus of the medial pterygoid plate down to the Mn • (Along with Superior pharyngeal constrictor) • Marks the posterior border of the vestibular side of the cheek (posterior border of buccinator) • Connects the buccinator and the superior pharyngeal constrictor o Inserts:  Orbiuclaris oris & skin at angle of mouth o Pierced by the parotid duct o Proprioceptive fibers are derived from the buccal branch of V3 o Muscle innervation from the buccal branch of VII o Actions:  Assists with mastication but NOT innervated by V3  Move boluses of food out of vestibules & back towards molar teeth  Tense the cheeks during blowing & whistling  Assist w/ closure of mouth o Blood supply – facial & maxillary arteries IA nerve block injection o Needle passes through mucous MB & buccinator muscle & lies lateral to medial pterygoid o If needle passes posteriorly at level of Mn foramen – penetrates parotid – facial paralysis o If needle passes well below Mn foramen – penetrate medial pterygoid o

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Muscle Genioglossus

Origin Superior genial spine of mandible

Styloglossus

Styloid process of temporal bone

Muscles of Tongue Insertion Dorsum of tongue Lateral side & dorsum of tongue (some fibers go into the hyoglossus m.) Side of tongue Side of tongue

Action Protrudes apex of tongue through mouth Depresses ALSO Elevates & retracts tongue (during swallow)

Innervation C1 via ansa cervicalis via Hypoglossal nerve XII XII

Hyoglossus Hyoid bone Depresses side of tongue XII Palatoglossus Palatine aponeurosis Pulls tongue upward & XI via X (Anterior Fauces) backward - Muscles of Tongue o All muscles of tongue are innervated by CN XII (except palatoglossus muscle – pharyngeal plexus [CN XI via X])  Damage to what CN leads to movement of the tongue toward the side of the damage?  CN XII o Blood supply – lingual artery; venous drainage into internal jugular vein o Extrinsic muscles:  Anchor tongue to skeleton  Control protrusion, retraction, & lateral movements of tongue  Genioglossus, Hyoglossus, Styloglossus, Palatoglossus (Decks say Palato IS an extrinsic, Netter’s doesn’t—Go with Decks) • Lingual nerve, hypoglossal nerve, & submandibular duct are all superficial to the hyoglossus (lingual artery is not) o Intrinsic muscles:  Lie entirely w/in tongue itself  Named according to spatial plane: longitudinal, transverse, vertical  Fibers contract to squeeze, fold, & curl the tongue - NOTE the “Exceptions” C1 via XII  Genioglossus (should be just XII) for the extrinsic tongue muscles   Thyrohyoid (should be just ansa cervicalis) for the strap muscles   Geniohyoid!! - Taste buds: o Associated w/ peg-like projections on the tongue mucosa called lingual papillae o Contain a cluster of 40-60 gustatory cells as well as many more supporting cells o Each gustatory cell is innervated by a sensory neuron o Have a turnover rate of 30 days, and are located on ventral and dorsum of the tongue?? o Kinds of Lingual papilla:

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Filiform: (think MILI, like Millions) • Most numerous, small cones arranged in V-shaped rows paralleling the sulcus terminalis on anterior 2/3 of tongue • Characterized by absence of taste buds & increased keratinzation (DON’T Taste, just like MILI didn’t sing) o Filiform papillae are the lingual papillae with the thickest keratin (think Mili Vanilli wore lots of Makeup) Fungiform:, FUNGUS are on the Tip and SIDES • Mushroom-shaped, found on tip & sides of tongue • Most likely to be damaged by a tongue laceration • Taste buds innervated by CN VII Circumvallate: • Largest but fewest in number (7-12), arranged in an inverted V-shaped row on back of tongue • Associated w/ ducts of Von Ebner’s glands • Have many taste buds, which are innervated by CN IX Foliate: • Found on lateral margins as 3-4 vertical folds • Taste buds innervated by both CN VII & CN IX Where are the taste buds found on the dorsum of the tongue?

Muscle Stylopharyngeus

Palatopharyngeus Salpingopharyngeus -

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Longitudinal Muscles of Pharynx Insertion Styloid process Posterior and superior margins of Thyroid cartilage & muscles of pharynx (Passes between the superior and middle pharyngeal constrictors) Hard palate; aponeurosis of soft palate Thyroid cartilage & muscles of pharynx Cartilage of auditory tube Muscles of pharynx Origin

Action Elevates pharynx & larynx

Elevates pharynx Elevates nasopharynx??, opens auditory tube Stylopharyngues – innervated by the glossopharyngeal nerve (the other two are innervated by CN XI via X -- pharyngeal plexus) Soft palate: o Blood supply – lesser palatine artery/vein o All muscles of soft palate (except one) are innervated by CN IX & X (pharyngeal plexus)  Exception: tensor veli palati m. – innervated by nerve to the medial pterygoid, a branch of V3 o Anterior zone of the palatal submucosa contains fat o Posterior zone contains mucous glands o Attached inferolaterally to tongue by the glossopalatine archs (Palatoglossal arch?) o Connected to lateral wall of pharynx by the pharyngopalatine arches (Palatopharyngeal arch) o Palatal salivary glands – found beneath mucous MB of the hard & soft palate (mostly mucous) o Five paired skeletal muscles of the soft palate:  1) Palatoglossus – closes oropharyngeal isthmus  2) Palatopharyngeus – • Elevates pharynx • Contraction during swallowing causes a fold in the posterior wall of the pharynx  3) Levator veli palati – • Elevates soft palate during swallowing & yawning • Innervated by X (XI via X) • Extrinsic muscle of the soft palate • Inserts in a palatine aponeurosis • From cartilage of Eustachian tube and petrous portion of temporal bone to the palatine aponeurosis of soft palate  4) Tensor veli palati – • Tenses palate & opens mouth of the auditory tube during swallowing & yawning • Curves around the hamulus (if hamulus is fractured, actions of this muscle are affected) • From the scaphoid fossa of the medial pterygoid plate, spine of the sphenoid bone, and cartilage of Eustachian tube to the palatine aponeurosis of the soft palate • Innervated by V3  5) Uvular – raises & shortens the uvula to help seal oropharynx from nasopharynx o Uvula – suspended from the soft palate  Innervated by pharyngeal nerve plexus • Unilateral nerve damage causes uvula to deviate to the opposite side (THE ODD BALL in that rule) • When uvular muscle contracts, the muscle on the intact side pulls the uvula toward that side  Bifid uvula: • Results from failure of complete fusion of palatine shelves Pharyngeal Constrictors (Circular Muscles)

Superior Pharyngeal constrictor  From pterygoid hamulus, pterygomandibular raphe, posterior portion of the mylohyoid line and side of the tongue • All attach to the median raphe of the pharynx and the pharyngeal tubercle of the occipital bone  Constricts the wall of the upper pharynx during swallowing  Innervated by X  Lateral wall of the Oropharynx  Behind the Mandible  Superior and Middle Constrictors are split by CN IX (glossopharyngeal) and the Stylopharyngeus muscle - See pp 636 ECA 2nd Ed. o Middle Pharyngeal Constrictor  From the stylohyoid ligament and the greater & lesser horns of the hyoid bone to the median raphe of the pharynx  Constricts during swallowing  Innervated by X  Behind the Hyoid bone o Inferior Pharyngeal Constrictor  Arises from the oblique line of the thyroid cartilage and side of cricoid cartilage to the median raphe of the pharynx  Constricts during swallowing  Innervated by X  Behind the Thyroid and Cricoid cartilages • The lower end is referred to as the cricopharyngeal muscle, which is continuous with the esophageal muscle fibers Circular Muscles of Pharynx Muscle Origin Insertion Action Superior constrictor Medial pterygoid plate, pterygoid hamulus, Median raphe & pharyngeal Constricts upper pharynx pterygoimandibular raphe; mylohyoid line of mandible, tubercle of skull side of tongue Middle constrictor Greater & lesser horns of hyoid; stylohyoid ligament Median raphe Constricts lower pharynx Inferior constrictor Arch of cricoid & oblique line of thyroid cartilages Median raphe of pharynx Constricts lower pharynx o

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Styloid Process Muscles o Stylohyoid  Innervated by VII  Perforated near its insertion at the hyoid bone by the tendon of the 2 bellies of the digastric bone  Elevates and retracts the hyoid bone that elongates the floor of the mouth o Stylopharyngeus  Innervated by IX (only muscle IX hooks up)  Passes between superior and middle constrictors  Elevates the larynx and pharynx during swallowing and speaking o Styloglossus  Innervated by XII  Some fibers interdigitate with hyoglossus muscle  Elevates and retracts the tongue during swallowing  One of the 4 Extrinsic muscles of the tongue Fauces o Anterior pillars form the glossopalatine arch (aka palatoglossal arch)  The arch attaches the soft palate laterally to the tongue  Within the arch – palatoglossus muscle –elevates tongue & narrows the isthmus of the fauces o Posterior pillars form the pharyngopalatine arch (aka palatopharyngeal arch)  The arch attaches the soft palate to the lateral wall of the pharynx  Within the arch – palatopharyngues muscle – elevates pharynx, helps close nasopharynx, narrows the isthmus of the fauces, & aids in swallowing o Palatine tonsils:  Consist predominantly of lymphoid tissue  Found between the two arches in an area called the isthmus of the fauces Retropharyngeal or Prevertebral space o Lateral boundary at level of oropharynx is the carotid sheath (not pterygomand. raphe, medial pterygoid, or stylopharyngeus m) o NOTE: retropharyngeal space lies between buccopharyngeal fascia & prevertebral fascia  Infection can spread from pharynx to mediastinum Strap Muscles (Infrahyoid Muscles) o Depressors of larynx & hyoid after they have been drawn up w/ pharynx to swallow (deglutition) o Lie between deep fascia & visceral fascia over the thyroid gland, trachea, & esophagus o Innervated by ansa cervicalis (aka cervical plexus) from C1,2,3 (except thyrohyoid – C1 fibers via CN XII) o Sternothyroid

Sternohyoid Thyrohyoid ***Boards ? said it WAS innervated by ansa cervicalis, and Geniohyoid was only one not  Anatomy notes say “Infrahyoids, EXCEPT thyrohyoid (C1 via CN XII)”  Maybe that one Q thinks that C1 (via CN XII) counts as part of ansa cervicalis o Omohyoid Muscle Origin Insertion Action Sternohyoid Manubrium of the Body of the hyoid Depresses the hyoid after sternum swallowing Sternothyroid Posterior surface of the Oblique line of the Depresses the larynx manubrium of the thyroid cartilage after swallowing sternum Omohyoid Inferior Belly: Superior Superior Belly: Inferior Depress the hyoid bone border of the scapula border of the hyoid bone after the bone has been near the suprascapular elevated. Retracts and notch steadies the bone * Then goes through a fibrous attachment of the clavicle Thyrohyoid Oblique line of the Inferior border of the Depresses the hyoid bone **Does not raise the lamina of the thyroid body and the greater horn and if the hyoid is fixed, hyoid (it’s infrahyoid, cartilage of the hyoid draws the thyroid baby!) cartilage superiorly o o

Innervation C1, C2, C3 (ansa cervicalis) C2, C3 (ansa cervicalis) C1, C2, C3 (ansa cervicalis)

C1 via XII (also to the Geniohyoid, and to the Genioglossus)

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Suprahyoid muscles: o Raise the hyoid during swallowing o Assist lateral pterygoid in depressing Mn o Assists posterior fibers of temporalis in retraction of Mn Muscle Origin Insertion Digastric Posterior Belly Both bellies end in an (Longest): Mastoid intermediate tendon that notch of the temporal perforates the stylohyoid bone muscles and is connected Anterior Belly: Digastric to the horn of the hyoid fossa of the mandible Stylohyoid Styloid process Body of the hyoid (Perforated by the digastric intermediate tendon) Mylohyoid Mylohyoid line of Median fibrous raphe mandible and the body of the hyoid bone **If fall on nail in submental region, first muscle penetrated

Geniohyoid

Mental spine (Genial tubercles)

Body of the hyoid

Action Elevates the hyoid and helps lateral pterygoids open the mouth by depressing the mandible

Innervation Anterior Belly: V3 (Mylohyoid n. branch) Posterior Belly: VII (SAME AS Stylohyoid)

Elevates and retracts the hyoid to elongate the floor of the mouth

VII

Elevates hyoid and raises floor of mouth during swallowing, pushes tongue upward or forward **Can help depress the mandible or open the mouth **Sublingual gland is located superior to the mylohyoid muscle

Mylohyoid n. branch (V3)

Elevates and draws the hyoid forward shortening the floor of the mouth When hyoid is fixed, also helps retract and depress the mandible

C1 via XII (also to the Thyrohyoid) **C1 Ventral primary ramus contributes to the superior root of the ansa cervicalis, which then jumps on XII to get to the geniohyoid (thyrohyoid also)

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Muscles of the Larynx o ALL (but the cricothyroid) of the intrinsic muscles of the larynx receive their innervation from the inferior (recurrent) laryngeal nerve (of CN X) o Posterior cricoarytenoid  Helps maintain a wide airway through the larynx Muscle Origin Insertion Action Innervation Cricothyroid Anteriolateral part of Inferior aspect and Stretches and tenses External branch of cricoid cartilage inferior horn of the vocal cords superior laryngeal nerve thyroid cartilage of X (**Superior laryngeal continues as internal branch that pierces thyrohyoid membrane and does sensory above the vocal cords) Posterior Posterior surface of the Attaches to the muscular ONLY muscle that Recurrent laryngeal Cricoarytenoid laminae of the cricoid process of the arytenoid ABDUCTS the vocal nerve of the vagus cartilage cartilage folds and widens the (Inferior Laryngeal) rima glottidis (space between the vocal folds) Oblique Arytenoids Arytenoid cartilages Attach to opposite Close the inlet of the Recurrent laryngeal arytenoid cartilage larynx by adducting the nerve of the vagus **(Some fibers continue rima glottidis (Inferior) superiorly as the Aryepiglottic muscle) Transverse Arytenoid Arytenoid cartilages Attach to opposite Close the inlet of the Recurrent laryngeal arytenoid cartilage larynx by adducting the nerve of the vagus rima glottidis (Inferior) Aryepiglottic Recurrent laryngeal nerve of the vagus (Inferior) Thyroepiglottic Recurrent laryngeal nerve of the vagus (Inferior) Thyroarytenoid Recurrent laryngeal nerve of the vagus (Inferior) Lateral Cricoarytenoid Recurrent laryngeal nerve of the vagus (Inferior) Vocalis Derived from the Recurrent laryngeal Pulls on the True and Thyroaryteniod muscle nerve of the vagus changes pitch **Located in the vocal (Inferior) folds themselves - ALSO in the Larynx o Conus Elasticus  Most superior portion is thickened and forms the vocal ligament o Vocal Ligament - The cricoid cartilage is cut twice in a sagittal plane (splits the body in left and right halves) o Provides a backstop when doing automatic tracheotomy o The thyroid cartilage, arytenoid cartilage, epiglottis & 2nd tracheal cartilages would not be cut twice UPPER LIMB MUSCLES - Axilla o Boundaries: (Pyramid)  Medial wall – upper 4-5 ribs & their intercostal muscles, and the serratus anterior muscle  Lateral wall – humerus (specifically the coracobrachialis & bicep muscles in the biciptial groove)  Posterior wall – scapula, subscapularis, teres major, & latissimus dorsi muscles  Anterior wall – pectoris major, minor, & subclavius muscles  Base – axillary fascia or skin o Contents:  Axillary vessels

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Branches of the brachial plexus Both heads of the biceps brachii Coracobrachialis

Muscle Pectoris major Pectoris minor Latissiums dorsi Deltoid Teres major Teres minor

Muscles of the Axilla Nerve Innervation Medial & lateral pectoral nerve from brachial plexus Medial pectoral nerve Thoracodorsal nerve from brachial plexus Axillary nerve (C5-C6) Lower subscapular nerve from brachial plexus Branch of Axillary nerve

Muscle Serratus anterior

Origin Outer surface and superior borders of first 8 to 9 ribs

Pectoralis minor

Coracoid Process

Subclavius Trapezius

Action Flexes, adducts, & medially rotates arm Depresses the scapula Adduct, extends & medially rotates the arm Abducts arm, post. Fibers extend & anterior fibers flex Adducts, extends & medially rotates the arm Rotates the arm laterally

Muscles of the Shoulder Insertion Action Insert on the ventral Pulls scapula forward & aspect of the vertebral downward preventing “winging” border of the scapula Also rotates scapula upward to abduct the arm above 90 degrees Pulls scapula forward & downward Draws clavicle downward Inserts into the upper and medial border of the Spine of the Scapula

Levator scapulae Rhomboideus major Rhomboideus minor

Muscle Triceps Brachii

Origin Scapula & humerus

Brachialis Brachioradialis Biceps Brachii

Humerus Humerus Scapula (coracoid process & supraglenoid tubercle)

Elevates scapula, draws head back, adducts scapula, braces shoulder, draws scapula downward Elevates & draws scapula medially Elevates & retracts scapula Elevates & retracts scapula

Muscle of the Arm Insertion Ulna (olecranon process)

Nerve Innervation Radial

Ulna (coronoid process Radius (styloid process) Radius (tuberosity)

Musculocutaneous Radial Musculocutaneous

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Innervation Long thoracic nerve (C5, C6, C7) Medial pectoral nerve Nerve to subclavius, C5, C6 Accessory nerve

Dorsal scapular nerve Dorsal scapular nerve Dorsal scapular nerve

Action Primary Extensor of the forearm Flexes the forearm Flexes the forearm MEDIAL rotates the arm Flexes the forearm & arm, supinates the forearm **Primary supinator at the radio-ulnar joint **Flexion at the glenohumeral joint **Flexion at the humeroulnar joint

Radial nerve is most commonly injured in a mid-humeral shaft fracture, because it runs in the radial (spiral) groove of the humerus Coracoid Process o A break would affect the biceps brachii and the pectoralis minor muscles (Pec major inserts into arm) And one more factoid: o The pronator quadratus m. is the primary pronator of the forearm (assisted by the pronator teres m.) Triangle of auscultation

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Bounded by the upper border of the latissimus dorsi, the lower border of the trapezius, & the medial margin of the scapula Site where breathing sounds can be heard most clearly Floor is formed by the rhomboid major

ABDOMINAL & PELVIC MUSCLES

Muscle Transversus abdominis Internal abdominal oblique **Along with the aponeuroses of the transverses, forms the conjoint tendon

Rectus abdominis **Linea alba splits the muscle and 3 tendinous bands horizontally (6 pack) External abdominal oblique

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Muscles of Anterior Abdominal Wall -- (TIRE – from Deep to Super) Origin Insertion Action Compresses abdomen Lateral half of the inguinal ligament, the iliac crest, and the thoracolumbar fascia

Inferior borders of the cartilages of the last 3 to 4 ribs, the linea alba, pubic crest, and pectineal line

2 tendons Lateral attaches to the pubic crest Medial interlaces with the tendon of the opposite side to arise from the pubic symphysis Fleshy digitations fro the external surface and inferior borders of lower 8 ribs

Attaches to the 5th, 6th, and 7th ribs and the xiphoid process

Attaches to the anterior half of the iliac crest, anterior superior iliac spine, and into a broad aponeurosis along a line from the 9th costal cartilage to the anterior superior iliac spine. The aponeurosis inserts into the midline linea alba

Compresses abdomen; lateral rotation, acting alone it bends the vertebral column laterally and rotates it to bring the shoulder of the opposite side forward **Nerves of the anterior abdominal wall lie immediately deep to this muscle Flexes vertebral column, tenses abdomninal wall, and depresses the ribs

Compresses abdomen; lateral rotation, acting alone it bends the vertebral column laterally and rotates it to bring the shoulder of the same side forward

Innervation Lower intercostal, iliohypogastric & ilioinguinal nerves Lower intercostals (T7T11), subcostal (T12) iliohypogastric, & ilioinguinal nerves (L1)

Lower intercostal nerves (T7-T11), and the subcostal nerve (T12)

Lower intercostal nerves (T7-T11)

Cremaster muscle o Arises from the middle of the inguinal ligament and is a continuation of the internal abdominal oblique muscle o Draws testes upward o Innervated by the genital branch of the genitofemoral nerve (L1 and L2) o After passing through the inguinal ring, the muscle fibers of the cremaster form a series of loops making up the cremaster fascia which surrounds the spermatic cord Posterior abdominal muscles: o Psoas major & minor – innervated by lumbar plexus o Quadratus lumborum  From the transverse process of L3-5, the iliolumbar ligament, and the iliac crest to the lower border of the last rib and the transverse processes of L1-3 vertebrae  Flexes the lumbar vertebral column, fixes the 12th rib during inspiration  Innervated by lumbar plexus (Subcostal nerve T12 and L1-3) • Above the muscle, the diaphragm forms the lateral arcuate ligament o Iliacus – innervated by femoral nerve o Dorsal rami innervate erector spinae muscles Respiratory muscles: o Diaphragm, internal & external intercostals, subcostals, & transverses thoracic  Diaphragm is innervated by phrenic nerve; the others are all innervated by intercostal nerves o Diaphragm:  Muscle mostly responsible for quiet breathing

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Flat muscle in a dome-like shape that separates chest & abdominal cavities Arises from the xiphoid process, lower 6 costal cartilages and a lumbar portion (L1-L3) • Then the muscles converge and insert into the central tendon o The tendon is drawn downward and forward during inspiration  Inhaling – contraction of diaphragm pulls down on chest (via the central tendon), drawing in air via pressure differences • The vertical dimension of the thoracic cavity is increased chiefly by contraction of the diaphragm  Exhaling – contraction of abdominal forces the relaxed diaphragm upwards  Upper surface contacts heart & lungs; Lower surface contacts liver, stomach, & spleen  Innervated by the Phrenic nerve (“C3, 4, 5…keep the diaphragm alive”) • Travels through the thorax between pericardium & pleura o The phrenic nerve is the nerve lying in close relation to the surface of the pericardial sac (not the vagus nerve) • Right phrenic travels anteriorly to bronchial root and does NOT leave an impression (azygos v. does) • Phrenic nerve Sends off branches to innervate the parietal pericardium • Is in direct contact in the neck with the Infrahyoid fascia • Inability to move the diaphragm is associated with a total section of the spinal cord at C2 • Phrenic nerve passes anterior to which muscle  Anterior scalene  Has three openings: • Caval opening – (T8) o IVC o Right phrenic nerve • Esophageal opening – (T10) o Esophagus o R & L vagus nerves • Aortic opening – (T12) o Aorta o Azygos vein o Thoracic duct • MNEMONIC: “I 8 10 EGGs AAT 12” o I = IVC – T8; T10 – EG = esophagus, G – vaGus or (10 for CN X); A = Aorta, Azygos, T = Thoracic duct – T12 o External intercostals: (Girls gone wild Externs – lifting up their shirt!)  From rib to rib in a shoulder to belly button direction – “hands in pocket”  Pass from rib to rib & run at right angles to fibers of the intenal & innermost muscles  Continue toward sternum as the anterior intercostal MB  Active during inspiration and elevate the ribs  Innervated by the intercostal nerve, i.e. between 4th and 5th rib is the 4th intercostal space, so innervated by the 4th intercostal nerve – meaning there are only 11 intercostal nerve o Internal intercostals:  Right angle to External intercostals  Eleven on each side between ribs  From rib to rib in a sternum to pants pocket direction  Continue toward vertebral column as the posterior intercostal MB  The upper portions (upper 4 to 5 intercostal muscles) elevate the ribs  The lateral and posterior muscles, where fibers run more obliquely depress the ribs and are active during expiration  Innervated by intercostal nerves o Innermost intercostals:  Run is same direction as internal intercostals but are separated from them by nerves & vessels  Thought to elevate the ribs  Innervated by the intercostal nerves o Transversus thoracis:  From posterior surface of the lower portion of the body of the sternum and xiphoid process to the inner surface of costal cartilages 2-6  Depress the ribs  Innervated by the intercostal nerves Muscles of Inspiration o SCM – Accessory muscle – Christopher Reeves used this to breathe. o Scalenes (Ant, Middle, Post) – Accessory muscle o External intercostals o Interchondral part of internal intercostals o Diaphragm Muscles of Expiration o Internal intercostals (except interchondral part)

Abdominals (TIRE – Transversus abdominis, Internal oblique, Rectus abdominis, External oblique)  NOTE : the nerves of the anterior abdominal wall lie between transversus abdominis & internal oblique muscles Active Inspiration o Diaphragm descends o Rib joints are active o Lateral diameter of thorax increases o

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LOWER LIMB MUSCLES - Quadriceps femoris group o Rectus femoris:  Crosses the hip & knee joints  Flexes thigh at hip & extends leg at knee o Vastus lateralis, intermedius & medialis  All extend leg at knee - Muscles of the thigh – posterior group o All three:  Flex the leg & extend the thigh  Innervated by tibial nerve o Biceps femoris o Semitendinousus o Semimembranous - Muscles of the thigh – anterior group o Sartorius  Flexes leg & thigh  Abducts thigh - Femoral triangle: o Contains the femoral V.A.N. - Unhappy triad: MCL, meniscus, & ACL -

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NERVOUS SYSTEM Embryology: o Neural Plate→Neural Tube  Prominent growth of neural tissue causes folding of the embryo during the 4th week of development • This gives it a C-shaped curvature  Neural plate forms by Day 19 in the dorsal midline of the embryo  A rostrocaudal groove appears on the midline & invaginates as the lateral borders rise to form the neural folds  The neural folds begins to move together & fuse, converting the neural plate into a neural tube  The Notochord induces ectoderm to form neuroectoderm, hence promoting formation of the neural plate  The Prochordal Plate (Buccopharngeal) and the cloacal plate only have 2 layers epi and hypoderm o Neural Tube  The neural tube develops into the CNS  Initially the neural tube is separated from the surface ectoderm by neural crest cells  Caudal end – develops into the spinal cord • Basal plates – motor part of CNS • Alar plates – sensory part of CNS – Alar does Afferents.  Rostral end – develops into the brain • 3 parts: rhombencephalon, mesencephalon, prosencephalon o Neural crest:  Band of neuroectodermal cells that lies dorsolateral to developing spinal cord  Clusters of cells (neural crest cells) develop into: DRG cells, spinal autonomic ganglion cells, chromaffin cells, neurolemma cells (Schwann cells), integumentary pigment cells (melanocytes), & meningeal covering of brain & spinal cord Nervous tissue has two classes of cells: o 1) Neurons: nerve cells  Transmit nerve impulses  Basic unit of the nervous system – activities of the system are carried out it at the neuron level o 2) Neuroglial cells: nerve glue  Provide support & nourishment for neurons 1) Neurons: o Structure  Cell body (perikaryon) • Contains nucleus & most of the cytoplasm • Located mostly in the CNS as clusters called nuclei – some found in periphery as ganglia

• When the cell body is destroyed all of its fibers degenerate and die • Synthesizes axoplasm that is needed for increasing axon length • Contains Nissl bodies (rough ER); not found in axon or axon hillock  Dendrites • Process that send the impulse toward the cell body • May be one or many dendrites – some neurons lack dendrites  Axon (nerve fiber) • Process that send the impulse away from the cell body • Only one axon per neuron o Classified according to:  1) Structure (by number of processes) • Bipolar or Unipolar or Multipolar (most common)  2) Function • Motor or Sensory or Mixed o Myelination  Myelin formed by Schwann cells in PNS & oligodendrocytes in CNS  Node of Ranvier is junction between two Schwann cells o Neurolemma  The outermost portion of a nerve fiber (Don’t call the myelin sheath the outer!!!!)  The nucleated layer of Schwann cells that surrounds the myelin sheath  So, from inside out: axis cylinder→myelin sheath→neurolemma o Motor Neurons  Babinski Sign • In adults, a positive Babinski sign means damage to upper motor neurons • In newborns, a positive sign is normal - 2) Neuroglia: o Non-neuronal tissue of CNS that performs supportive & other ancillary functions o Composed of various types of cells collectively called neuroglial or glial cells o With the exception of the microglia, which derives from mesoderm, all other neuroglia cells form from ectoderm Neuroglia Cells that support neurons Structure Function CNS Astrocytes Stellate w/ numerous processes Form structural support between capillaries & neurons w/in CNS, Blood Brain Barrier Oligodendrocytes Similar to astrocytes but w/ shorter & fewer Form myelin in CNS, guide development of neurons processes w/in CNS – myelinates multiple CNS axons Microglia Minute cells w/ few short processes Phagocytize pathogens & cellular debris w/in CNS. Mesodermal origin (M for M, others are from Act like macrophages which also derive from Ectoderm) mesoderm. Ependymal Columnar cells that may have ciliated free surface Line ventricles & central canal w/in CNS where CSF is circulated by ciliary motion PNS Satellite cells Small, flattened cells Support ganglia w/in PNS Schwann cells Flattened cells arranged in series around axons or Form myelin w/in PNS – only myelinates 1 axon dendrites Promote axonal regeneration -

Spinal cord: o Cylindrical, occupies ~ upper 2/3 of vertebral canal, & is enveloped by the meninges o Centrally located gray matter & peripherally located white matter o Ends at ~L1 in adults & at ~L3 in young children  Dura & arachnoid continue to S2 where arachnoids fuses w/ filum terminale (after fusion it is called the coccygeal ligament) o Main areas of spinal cord:  Gray matter • H-shaped, centrally located, consists of nerve cell bodies & unmyelinated nerve fibers • Gray commissure – center of the “H” – connects two paired posterior (dorsal) horns & anterior (ventral) horns • Anterior horn→motor o Cell bodies of somatic motor system lie w/in the ventral horn o Cell body of a motor neuron in a spinal reflex arc is located in anterior gray column (ventral horn) of the spinal cord o Patellar (knee-jerk) reflex: L4 o Biceps reflex: C5 o Triceps reflex: C7

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o Achilles reflesx: S1 Lateral horn→autonomic • Posterior horn→sensory Central canal: • w/in gray commissure & filled w/ CSF White matter: • Composed primarily of myelinated axons (because it’s fatty) • Surrounds gray matter

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o Fasciculus gracilus – legs (Think Graceful legs and straight down) o Fasciculus cuneatus – arms Spinal taps o Lumbar puncture needle inserted in space between L3-L4 (or between L4-L5)  Needle enters subarachnoid space which is filled w/ CSF (pia is not pierced) o CSF can be aspirated most safely by inserting the needle between L3 & L4 since the spinal cord usually does not extend below L2 Spinal nerves: o 31 pairs; all spinal nerves are mixed – made up of ventral & dorsal roots  8 cervical – 12 thoracic – 5 lumbar – 5 sacral – 1 coccygeal  The cauda equina consists of the roots of the lumbar & sacral spinal nerves o Ventral and Dorsal roots leave the spinal cord, immediately join to form the Spinal Nerve, then 3 branches, 1 to sympathetic chain ganglion, 1 to the Ventral Rami (i.e. intercostals), 1 to Dorsal Rami (i.e. intrinsic

muscles of the back)  Then the anterior rami can branch to form Lateral and Anterior cutaneous branches  The intercostals nerves course between the innermost and the inner intercostal muscles  Intercostals (somatic nerves) are connected to the sympathetic chain ganglia via the rami communicantes • Like how the greater splanchnic nerve comes from rami communicantes from T5-9 Ventral roots  Contain axons of motor neurons (also ANS stuff)  Cell bodies located in spinal cord  Upon exit, become anterior rami (mixed) – supply body wall & limbs • In cervical, brachial, lumbar, & sacral regions the anterior rami of the spinal nerves unite to form plexuses o These plexuses give rise to other nerves for distribution to muscle, skin, etc. Dorsal roots  Contain axons of sensory neurons  Cell bodies located outside spinal cord in dorsal root ganglia  Upon exit, become posterior rami (mixed) – supply skin & deep back muscles Hey, if you’re confused, look at a picture somewhere

Spinal Cord tracts o Columns of white matter w/in spinal cord that conduct impulses to CNS (ascending) & away from CNS (descending) SPINAL CORD TRACTS Ascending tracts Function Anterior spinothalamic Conducts sensory impulses for touch & pressure Lateral spinothalamic (side of lateral horn) Conducts pain & temperature impulses Fasciculus gracilis (back in the midline) & fasciculus cuneatus Conducts sensory impulses from skin, muscle, tendons, & joins; (back offset) (THINK GRACEFUL LEGS) also touch localization (conscious proprioception) Posterior spinocerebellar (back corners) Conducts sensory impulses from one side of body to same side of cerebellum for subconscious proprioception Descending Tracts Function Anterior corticospinal (Front Midline) Conducts motor impulses from cerebrum to spinal nerves & outward through anterior horn for coordinated movement Lateral corticospinal (Just next to dorsal horn, inside Post. Conducts motor impulses from hemisphere to spinal nerves through Spinocer.) anterior horns for coordinated movments Tectospinal (Front offset) (Night at the Roxbury –TECHNO head Conducts motor impulses to cells of anterior horns & eventually to shake) muscles that move the head Rubrospinal (In lateral grooves, in front of lat. Corticosp.) Conduct motor impulses concerned w/ muscle tone & posture Vestibulospinal (Front really offset) Regulate body tone & posture (equilibrium) in response to

Anterior & medial reticulospinal & lateral reticuloalspinal

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movements of head Control muscle tone & sweat gland activity

Meninges o Three protective tissue layers covering CNS o The structures involved in meningitis (inflammation of meninges) – if severe can become encephalitis (inflammation of brain) o Dura mater:  Outermost MB – a fused, double layer of tough fibrous CT  Layers separate to form venous sinuses in the cranial cavity  Endosteal layer adheres tightly to inner surface of the cranium  Meningeal layer forms partitions (folds) that extend between regions of the brain o Arachnoid:  Delicate middle MB – adheres to dura mater but is separated from pia mater by subarachnoid space – contains CSF o Pia mater  Innermost MB – delicate vascular MB of loose CT – adheres closely to brain & spinal cord Outside the skull: “SCALP” o Skin, CT, Aponeurosis, Loose CT, Pericranium Cerebrospinal fluid o Clear, colorless fluid formed by the choroid plexuses w/in the lateral, 3rd & 4th ventricles o Produced by filtration, primarily from tufts of capillaries that protrude into all four ventricles  Ependymal cells also produce CSF – they line the ventricles, central canal of spinal cord, & choroid plexuses o Fluid enters the subarachnoid space through three foramina of the 4th ventricle o Choroid plexuses regulate intraventricular pressure by secretion & absorption of CSF o CSF along w/ ligamentous walls of vertebral canal protect spinal cord from injury Dura mater (continued): o Two vertical folds  Falx cerebelli – separates hemispheres of cerebellum; contains occipital sinus  Falx cerebri – separates the cerebral hemispheres; contains inferior & superior sagittal sinuses o Two horizontal folds  1) Tentorium cerebelli • Separates occipital lobes from the cerebellum • Contains straight, transverse, & superior petrosal sinuses (NOT inferior petrosal sinus)  2) Diaphragma sellae • Forms roof of sella turcica; a small central opening allows passage of infundibular stalk of the pituitary BRAIN o Blood-brain barrier (BBB):

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Protected by the CIA: • Choroid plexus epithelium • Intracerebral capillary endothelium • Arachnoid  Glucose & amino acids cross by carrier-mediated transport mechanism  L-dopa used to treat Parkinson’s, since dopamine does not cross the BBB Consists of several regions: TDMMMS  Forebrain (prosencephalon) • Telencephalon & diencephalon derive from the forebrain  Midbrain (mesencephalon)  Hindbrain (rhombencephalon) • Metencephalon and Myelencephalon derive from the Hindbrain Each portion of brain consists basically of three areas:  Gray matter – composed primarily of unmyelinated nerve cell bodies  White matter – composed basically of myelinated nerve fibers  Ventricles – spaces filled w/ CSF Cerebrum:  Located w/in telencephalon & is the higher forebrain  Consists of five paired lobes w/in two convoluted cerebral hemispheres (connected by corpus callosum)  Accounts for 80% of brain’s mass  Deals w/ higher functions – perception of sensory impulses, instigation of voluntary movement, memory, thought, reasoning  Two layers of cerebrum: • Cerebral medulla – thickened core of white matter • Cerebral cortex – thin, wrinkled gray matter covering each hemisphere Diencephalon:  Major autonomic region of forebrain – almost completely surrounded by cerebral hemispheres of the telencephalon  Chief components – thalamus, hypothalamus, epithalamus, & pituitary gland (just posterior pituitary)  The 3rd ventricle forms a midplane cavity w/in the diencephalon Hypothalamus:  Is the inferior portion of the diencephalon & forms roof & ventrolateral walls of the 3rd ventricle  Endocrine control • Regulates hormone synthesis in anterior pituitary • Synthesizes & releases oxytocin & ADH – water/salt balance\ • ADH – supraoptic nucleus; Oxytocin – paraventricular nucleus -- (Think LOW oxygen when you PARAshute)  Regulation of ANS  Temperature control (anterior hypothalamus – think A/C: Anterior = Cooling)  Eating behaviors • Lesions of ventromedial HTh→obesity • Lesions of lateral HTh→severe aphagia • Lesions of supraoptic nuclei→diabetes insipidus (polydipsia & polyuria result from deficient ADH)  Sexual maturation & childbirth Thalamus:  Thalamic nuclei: • DOESN’T regulate Breathing – Medulla Ob does • Lateral Geniculate nucleus – visual • Medial Geniculate nucleus – auditory (PUT your fingers in your ears  POINT MEDIALLY) • Ventral posterior nucleus – sensory o Medial part – body senses o Lateral part – facial sensation • Ventral anterior/lateral nuclei – motor o o o

A – Lateral Ventricle B – Corpus callosum Identify the thalamus in the sketch above: “C”

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D – Internal Capsule E – Basal Ganglia (Caudate, Putamen, Pallidum, Substantia Nigra, Nucleus accumbens, Subthalamic Nucleus)

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Most of the fibers ascending or descending to the cerebral cortex transverse the internal capsule  The fiber tracts passing from the thalamus to the cortex are found in the internal capsule

Four ventricles:  NOTE: formation of the brain begins w/ differentiation of the cephalic end of the hollow neural tube • Hollow spaces persist as ventricles w/in the brain  1&2) Two lateral ventricles • Hollow C-shaped spaces w/in right & left cerebral hemispheres • Large mass of gray matter that bulges into the floor and lateral aspect of the ventricle is the caudate nucleus  3) Third ventricle • Forms a median cavity w/in the diencephalon (forebrain)  4) Fourth ventricle: • Located in the metencephalon (hindbrain). • Contains two openings in its walls called Lateral apertures (foramina of Luschka) • Contains a single opening in its roof called Medial aperture (foramen of Magendie) • The apertures connect the ventricular system w/ the subarachnoid space • After circulating throughout the subarachnoid space, CSF is returned to the circulatory system by filtration through arachnoid villi (villi protrude mainly into the venous drainage sinuses of the cranial cavity) into the Superior Sagittal sinus  Two interventricular foramina of Monro – oval openings which provide communication between the third & lateral ventricles  The cerebral aqueduct in the midbrain connects the third & fourth ventricles  Obstruction of the cerebral aqueduct causes enlargement of the two lateral & third ventricles (not the fourth) • Referred to as a non-communicating hydrocephalus – which means lateral ventricles are not in communication w/ subarachnoid space o Excessive CSF in the ventricles o Substantia Nigra (Black people are “DOPE”  Uses dopamine as predominant neurotransmitter for S.N. (not for olivary nucleus or lateral reticular nucleus) o Cerebellum  Consists of the vermis (medial) & two cerebellar hemispheres  External anatomy: • Each hemisphere has an anterior lobe, posterior lobe, & flocculonodular lobe  Internal anatomy: • Cerebellar cortex o 3 layers (think MPG): Medullary, Purkinje, Granular • Arbor vitae o Subcortical white matter • Cerebellar nuclei  Circuitry: • Mossy fibers = excitatory fibers from the spinal cord, pons, & vestibular nuclei • Climbing fibers = excitatory fibers from the inferior olive nucleus • Golgi cells = fibers receiving input from mossy fibers & parallel fibers of the granule cells • Purkinje fibers = fibers receiving input from the climbing & parallel fibers AND inhibitory input from basket cells • Each granule cell sends its axon into the molecular layer, giving off collaterals at 90° angles = parallel fibers o The granule cell axons stimulate the distal dentrites for the Purkinje cells & Golgi cells o Purkinje fibers are the final common pathway for cortical output  They can stimulate OR can send a single axon through the granular layer & arbor vitae to inhibit the deep nuclei  Common symptoms of cerebellar dysfunction • Ataxia, Dysmetria, Nystagmus, Hypotonia, Intention tremor Cerebral cortex: o Extensive outer layer of gray matter of cerebral hemispheres o Cerebral lobes function primarily in voluntary movement, higher intellectual processes & personality (w/ the limbic system) o NOTE: basal nuclei – gray matter structures deep w/in each cerebral hemisphere – help control muscle activity o

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Area of Cerebral Cortex Precentral gyrus of frontal lobe Postcentral gyrus of parietal lobe (Think Dorsal meaning Sensory) Medial surface of the occipital lobe Parietal lobe (near base of postcentral gyrus) Temporal lobe (transverse temporal gyri) Frontal lobe

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Function Motor area (initiates voluntary contractions of skeletal muscle EX – Highly skilled, discrete hand movements depend on activity of the precentral gyrus Sensory area (receives sensory info regarding temperature, touch, pain, proprioception) Concerned with recognition of painful stimulus from the teeth **Sensations from Left face and Teeth are interpreted in the Right Parietal Lobe Visual area – visual center of the cerebral cortex is found here Taste area Hearing area – the primary auditory complex is found here (Higher intellectual functions) (Unable to Plan or Organize Behaviors) (Lacks Self-Discipline) (Anti-social Behavior) – PHINEAS GAGE Somatic associated area (Integration & interpretation center) Smell

Limbic system: o Includes brain structures involved in emotion, motivation, & emotional association w/ memory o Responsible for 5 F’s:  Feeding, Fighting, Feeling, Flight, & Sex (Ha, Ha) (as quoted from USMLE) Gate Theory of Pain (outdated???) o A controller system modulates sensory input so that there is a selective and integrative action occurring before impulses reach the first synapse for onward transmission.  The gate controller in this system is the substantia gelatinosa • Jello would fit through the gate BRAINSTEM o “Picture: ID – cross section of : pons, midbrain, medulla oblongata, spinal cord” o Corticobulbar tract  The fibers which separate from the corticospinal tract as it descends through the pons & medulla oblongata  Fibers of this tract innervate the motor nuclei CN V, CN VII, CN XII (perhaps also the nucleus ambiguus) 1) Which CN contralateral innvervation? CN 12 (also the upper part of 7 to the forehead, and most texts also say 2) o I think it could be 5, 7 upper, 12 (& even nulceus ambiguus) 2) What CN crosses corticobulbar? 12 o Same answer 3) Which tract of the corticobulbar only innervates to the contralateral side of the face? o I say it’s 7 lower o Hypoglossal n. (not sure)

http://sprojects.mmi.mcgill.ca/cns/histo/systems/motor/main.htm - for explanations Also see “lab” on desktop for explanation CN XII receives bilateral innervation CN V does, too CN VII lower is only contralateral N. ambiguus receives bilateral -

BRAINSTEM o Lower extension of brain where it connect to spinal cord o Neurological functions located in the brainstem include those necessary for survival  Breathing, digestion, HR, BP o Most cranial nerves come from brainstem o Motor nuclei are medial to sensory nuclei o Pathway for all fiber tracts passing up & down between peripheral nerves & spinal cord to higher brain o Midbrain:  Nerve pathway of cerebral hemispheres  Contains auditory & visual reflex centers o Pons:  Bridge-like structure which links different parts of brain  Serves as a relay staion from medulla to higher cortical structures of brain o Medulla oblongata:  Relay station for the crossing of motor tracts between spinal cord & brain

If the spinal tract of CN V were sectioned at the level of the caudal medulla, PAIN from the ipsilateral side of the face would be most affected Contains respiratory, vasomotor, & cardiac centers Has many mechanisms for controlling reflex activities (e.g., coughing, gagging, swallowing & vomiting) Medial lemniscus • Large ascending bundle of fibers, composed of 2nd order neurons, carrying proprioception & discriminatory touch sensations to the conscious levels •

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o BRAINSTEM NUCLEI: o LOOK UP CROSS SECTIONS OF MIDBRAIN, PONS, AND MEDULLA  ORIGIN OF CNS • BRAIN (2) o I o II • MIDBRAIN (2) o III o IV – Only CN from Dorsal Brainstem • PONS (4) o V (remember Spinal N. of V is from Medulla) o VI o VII o VIII • MEDULLA (4 – 5* if you count Spinal of V) o IX o X o XI o XII o CN III  Oculomotor • GSE fibers to all extraocular muscles except the superior oblique (trochlear nerve) and the lateral oblique (Abducens nerve)  Edinger-Westphal Nucleus • PreG parasym fibers, which give rise to GVE fibers with terminate on cells in the ciliary gaglion  Lesions • Ptosis, Eye looks down and out causing double vision, Mydriasis, and loss of accommodation • In cross section of the nerve, the parasym fibers surround the somatomotor o CN IV  Trochlear nuclei • located near central gray matter of the lower midbrain at the level of the inferior colliculi • Located on the Dorsal side of the brain – only nerve that comes from the back of the brainstem.  Lesions • Double vision on looking downward and awy from the affected side o CN V: • Sensations from the Left face and teeth are interpreted in the Right Parietal lobe • Touch receptors are most numerous per unit area in the tip of the tongue  Motor nucleus of V: • *Sends SVE fibers to muscles of mastication • Lower motor neuron control of the muscles of mastication is by way of the Motor nucleus of V • Monosynaptic jaw closing reflexes might be disrupted in Motor nucleus of V • Just medial to the Main Sensory Nucleus • Fibers are SVE and supply the 8 muscles of V3 • Joins sensory nuclear complex fibers to become Trigeminal Nerve  Trigeminal sensory nuclear complex: • Axons enter the pons through sensory root & terminate in 1 of 3 nuclei of trigeminal sensory nuclear complex: • 1) Mesencephalic nucleus: (“MeS” for Muscle Spindle and Phalic for P-DaLic) o Mediates proprioception (ex. Musclespindle) from the face o Primary sensory neurons of mechanoreceptors in the PDL –not in the main sensory nucleus of TG. o Cell bodies of the proprioceptive 1st order neurons are found in mesencephalic nucleus (not trigeminal ganglion)

Mediates Jaw jerk reflex  Only nucleus in the CNS that receives proprioceptive inputs from muscle spindles o Only example in which the primary sensory cell bodies reside within the CNS instead of in ganglia 2) Main sensory nucleus: (The Main role of V is sensation) o Discriminative touch of face o Mediates general sensation (ex. Touch) o **All sensory information from the face  fibers cross and ascend in the ventral TTT (Trigeminalthalamic Tract) to the VPM - M for “your ugly Mug”  From the rest of the body it goes to the VPL 3) Spinal trigeminal nucleus of V: (SPAINAL Spine pain/temp in lateral cord) o Mediates pain & temperature from head & neck (Oral Cavity) o Mx bone fracture next to central incisor…nociception terminates centrally in spinal subnucleus caudalis of V o If the spinal tract of the fifth cranial nerve were sectioned at the level of the caudal medulla, PAIN from the face would be most affected o The primary sensory neurons' nucleus of termination for pain from a Mx M2 is the spinal nucleus of V o The descending tract (down to the spinal nucleus) of V contains axons of primary sensory neurons o Fibers then cross and ascend in the ventral TTT (trigeminothalamic) tract to the VPM as well o

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Lesions  Sensory deficits  Loss of tactile, Proprioceptive, pain sensation, temperature, etc.  Motor deficits  From lower motor neuron involvement involving the muscles of mastication • Temporalis and masseter causes weak jaw closure • Pterygoid weak jaw opening (probably just the lateral pterygoid lesion would do this) o

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CN VI  Abducens nucleus • Located in the lower pons, ventral to the floor of the fourth ventricle near the midline • Provides GSE to the lateral rectus muscle  Lesions • Paralysis causes lateral rectus palsy, leading to medial deviation of the affected eye and diplopia CN VII  Main Motor Nucleus • To all the muscles of facial expression • NOTE the upper face receives bilateral innervation BUT the lower face receives contralateral innervation

• REFER TO Bell’s PALSY Superior Salivatory nucleus • Located posterolateral to the motor nucleus of VII • One group of fibers enters the superficial (greater) petrosal nerve and terminates in the ptergopalatine ganglion  Lacrimal glands • Another group of fibers travels in the chorda tympani nerve to reach the submandibular gangion  Submandbular and Sublingual glands – (Greater goes to Ganglion) Gustatory nucleus (Nucleus Solitarius)  actually VII, IX, and X • Solitary tract gives rise to the geniculate ganglion • The rostral portion of the nucleus of the solitary tract receives all the SVA fibers for taste, which pass in the seventh, ninth, and tenth CNs • The facial receives all the anterior 2/3rds of the tone • The taste afferents in the facial nerve arise from cells in the geniculate gangion Lesions • Flaccid paralysis of muscle of facial expression (upper and lower face) • Loss of corneal reflex (efferent limb) • Hyperacusis (due to stapedius muscle) paralysis • Loss of taste from anterior 2/3rds  means lesion is proximal to the sytlomastoid foramen since the chorda tympani joins the facial nerve in the middle ear • Bell’s Palsy o Lower motor neuron damage = ipsilateral problems o *Facial nerve:

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LMN lesion: • Affects BOTH upper & lower face • Causes an IPSILATERAL flaccid paralysis of facial musculature • A pt has a lower facial paralysis, where is the damage  facial nerve in the facial canal!!! o NOT after it leaves the stylomastoid foramen • Hyperactive  Spastic Paralysis • Hypoactive  Fasciculations, Atrophy, Flaccid Paralysis (Like in ALS) UMN lesion: • Affects ONLY lower face • Most commonly affects CONTRALATERAL face below the eyeball • Rt sided lower face paralysis caused by Contralateral (left side) Cerebrocortical damage

CN VIII  Vestibular Nuclei • Sensory from the Crista ampullaris of the semicircular canals and the maculae of the utricle and saccule  Cochlear Nuclei: • Input from the Organ of Corti, Spiral Ganglion CN IX  Glossopharyngeal nuclei • SVE fibers from the rostral nucleus amibiguus and supply the stylopharyngeus muscle • GVA fibers to the nucleus solitarius and supply the baroreceptors of the carotid sinus • SVA fibers carrying taste sensation from the posterior 1/3rd of the tongue and terminate in the nucleus Solitarius (aka gustatory nucleus) • GSA Fibers supplying the posterior tongue and pharynx carry the sensory limb of the Gag reflex o The motor limb of this reflex is carried by fivers from the nucleus ambiguous, which exits via the vagus nerve o Lesion  Up CN IX results in unilateral ipsilateral loss of gag reflex  Down CN X results in bilateral loss of gag reflex  Inferior Salivatory • PS nerve fibers to the Otic ganglion via Lesser petrosal nerve  hitchhikes on V3 (auriculotemporal) to the Parotid Gland CN X  Main Motor Nucleus • (aka the vagal part of the nucleus ambiguous) • Located in the anterior portion of the reticular formation and extends throughout the medulla • Sends motor fibers through the  Dorsal Motor Nucleus • Located in the floor of the 4th ventricle and ventral to sulcus limitans • PreG PS fibers – distributed to the PostG neurons supplying the viscera of the thorax and abdomen  Nucleus Solitarius (aka Gustatory nucleus)  VII, IX, and X • GVA fibers from the larynx, esophagus, and baroreceptors in the aortic arch and visceral abdominal/thoracic viscera • SVA fibers from epiglottis’ taste buds (present in newborns)  Nucleus Ambiguus • Sends SVE fibers to larynx, pharynx all the XI via X crap  Lesions • Weakness of the palate, loss of gag, and nasal speech occurs and possibly nasal regurgitation of food • Bilateral lesions of the vagus leads to paralysis of the pharynx and larynx  death from asphyxiation • Paralysis of an ipsilateal vocal cord may occur, because the recurrent laryngeal nerve supplies all of the laryngeal muscles, except the cricothyroid, which is supplied by the superior laryngeal nerve  In a nut shell • Nucleus solitarius = sensory (taste, gut distension, etc) – VII, IX, X • Nucleus ambiguus = motor (pharynx, larynx, upper esophagus) – IX, X, XI o Dorsal motor nucleus (parasympathetic) (to heart, lungs, upper GI) – X only • Baroreceptors o From IX  Carotid Sinus o From X  Aortic Arch • Each CN has a nucleus of its own name, EXCEPT: o I/II/VIII – special sense only o IX/X – these share nucleus ambiguous o VII/IX/X – share nucleus solitarius (aka gustatory nucleus) o XI – arises from cervical spinal cord – only called a CN because it sneaks up & exits skull w/ IX & X CN XI

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Spinal accessory nerve (not nucleus): • *Sends SVE fibers to SCM & trapezoid • XI via X explanation o Cranial root fibers originate from the caudal nucleus ambiguous to supply the intrinsic muscles of the the larynx o The fibers join CN X and finally reach the intrinsic laryngeal muscles through recurrenet laryngeal nerve  Lesions • Paralysis of the SCM (difficulty in turning head) and Trapezius (shoulder droop) o CN XII  Hypoglossal Nucleus • Located near the midline below the floor of the 4th ventricle in the caudal medulla • GSE fibers to intrinsic muscles of the tongue, genioglossus, hyoglossus, and Styloglossus  Lesions • Ipsilateral paralysis – deviation TOWARD o UMN – Unilateral Tongue weakness W/O atrophy  Bilaterally innervated upper, so NO atrophy o LMN – Unilateral Tongue weakness W/ atrophy (e.g. from tonsillectomy damaging CN XII) Anatomic Divisions of Nervous System o CNS  Brain & spinal cord  Control center of nervous system  Receives sensory input from PNS & formulates responses o PNS  12 pairs of cranial nerves  31 pairs of spinal nerves – 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, & 1 coccygeal  Afferent division: • Somatic sensory neurons – carry impulses from skin, fascia & joints • Visceral sensory neurons – carry impulses from viscera of body (hunger pangs, BP)  Efferent division: • Somatic (voluntary) – somatic motor neurons carry impulses to skeletal muscles • Autonomic (involuntary) – visceral motor neurons transmit impulses to smooth & cardiac muscles & glands o Sympathetic & Parasympathetic o See next section Autonomic Nervous System o Innervation to organs not usually under voluntary control o Cardiac muscle, smooth muscle, visceral organs/glands o Preganglionic neurons  Cell bodies are in CNS  Synapse in autonomic ganglia  Parasymp – originate in cranial nerves & craniosacral region • PreG PS fibers have their cell bodies in association w/ the nuclei of certain cranial nerves & in the anterolateral cell column of the grey substance of S2-4, A for AL, as • Preganglionic PS nerve fibers to the urinary bladder have their cell bodies in the spinal cord at the S2,3,4 level  Symp – originate in thoracolumbar (T1-L3) region • PreG S fibers to the head/neck have their cell bodies in the intermediolateral horns of the thoracic spinal cord • PostG S fibers to the head have their cell bodies in the cervical ganglia o Postganglionic neurons  Cell bodies in autonomic ganglia  Synapse on effector organs o SYMPATHETIC DIVISION:  Prepares body for intense physical activity in emergencies (fight or flight) through adrenergic effects  HR increases & blood glucose rises  Blood is diverted to skeletal muscles  Pupils & bronchioles dilate  Adrenal medulla releases Epi & NE  Preganglionic fibers • Release ACh • Carried by white rami  Postganglionic fibers • Release NE (except for BVs in skeletal muscles & sweat glands) • Carried by gray rami  ***Synapse in paravertebral or prevertebral ganglia o PARASYMPATHETIC DIVISION:

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 Conserves energy (rest & digest)  Decrease HR  Papillary & bronchiolar constriction  No effect on adrenal medulla  Maintains normality of body functions  Preganglionic & postganglionic fibers – release ACh Synapses between neurons are made in autonomic ganglia  PS NS – ganglia located in or near effector organs  Symp NS – ganglia located in the paravertebral chain NOTE: Most organs are innervated by both PS & Symp NS

Cranial Sutures o Coronal Suture  Separates Frontal bone from BOTH Parietal Bones o Sagittal Suture  Separates BOTH Parietal Bones o Lambdoid Suture  Separates BOTH Parietal Bones from Occipital Bone o Squamous Suture  Separates A Parietal Bone from the Temporal Bone -

FORAMINA:

Anterior Cranial Fossa: I  Cribriform plate perforations • Located in ethmoid bone • Contains olfactory nerves (CN I) o Middle Cranial Fossa: II-VI  Optic Canal – CN II (optic nerve), ophthalamic artery, central retinal vein (within optic nerve)  Superior Orbital Fissure – CN III, IV, V1, VI, superior ophthalamic vein NOT ophthalamic artery • Between the slit light openings between lesser & greater wings of sphenoid bone  Foramen rotundum – in sphenoid bone – carries maxillary nerve (V2) • Inferior orbital fissure – carries the maxillary nerve (V2) – AFTER IT HAS EXITED THE BRAIN  Foramen ovale – in sphenoid bone – carries mandibular nerve (V3) & the lesser petrosal nerve and accessory meningeal artery • Think: for CN V, it’s Standing Room Only (S. R. O.)  Spinosum – middle meningeal artery • Foramen spinosum – in sphenoid bone – carries middle meningeal artery & vein Posterior Cranial Fossa: VII-XII  Internal Auditory Meatus – CN VII, VIII • Canal running through petrous portion of the temporal bone • CN VII – enters meatus & emerges from stylomastoid foramen – between styloid & mastoid processes of temporal bone o Gives off five branches in the parotid gland – supplies motor innervation to muscles of facial expression o Anesthetic in parotid (during Mn block) paralyzes muscles of facial expression o Gives chorda tympani branch thru the petrotympanic fissure • CN VIII – enters meatus, then remains w/in temporal bone o Nerve fibers to cochlear duct (hearing), semicircular ducts & maculae (balance)  Jugular Foramen – CN IX, X, XI, internal jugular vein (Found in the Posterior Cranial Fossa) • Passage between the petrous potion of the temporal bone and the jugular process of the occipital  Hypoglossal Canal – CN XII  Foramen magnum – in occipital bone – contains medulla oblongata, vertebral arteries, & spinal accessory nerve, Medulla Oblongata o

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Mandibular foramen:  Location: • Above the occlusal plane & posterior to the Mn molars • On medial surface of ramus just below the lingula, midway between the anterior & posterior borders of the ramus

• Lateral to the medial pterygoid muscle Leads into Mn canal which opens into mental foramen below PM2 NOTE: incisive canal – a continuation of the Mn canal beyond the mental foramen & below incisor teeth NOTE: lingula – bony projection that serves as the attachment for the sphenomandibular ligament Contains inferior alverolar nerve, artery & vein • IA nerve ends at mental foramen by dividing into: o 1) mental nerve – supplies skin & mucous MB of mental region o 2) incisive branch – supplies pulp chambers of anterior teeth & adacent mucous MB Other foramina:  Carotid canal • Located in temporal bone • Contains internal carotid artery & sympathetic nerves (carotid plexus)  Nasolacrimal canal • Located in lacrimal bone/maxilla • Contains nasolacrimal duct  Foramen cecum – in frontal & ethmoid bones – contains emissary vein in fetal life  Sphenopalatine foramen – sphenopalatine artery/vein & nasopalatine nerve  Pterygoid canal – deep & greater petrosal nerves (these form the nerve of the pterygoid canal)  Pterygomaxillary fissure – PSA artery/vein/nerve & maxillary artery  Pterygopalatine canal – greater & lesser palatine artery/vein/nerve  Pharyngeal canal – pharyngeal branch of V2  Greater palatine foramen – in the palatine – carries greater palatine nerve, artery & vein  Lesser palatine foramen – carries lesser palatine nerve artery & vein  Stylomastoid foramen – in temporal bone– carries facial nerve  Mental foramen – in mandible – carries mental nerve, artery & vein  Petrotympanic fissure – in temporal bone – carries chorda tympani & anterior tympanic artery • Fracture involving petrotympanic fissure would affect the chorda tympani  Foramen lacerum – in temporal & sphenoid bones – carries artery of the pterygoid canal, greater & deep petrosal nerves (through the occluded cartilage)  Supraorbital foramen – in frontal bone – carries supraorbital nerve artery & vein  Infraorbital foramen – in sphenoid & maxilla – carries infraorbital nerve (V2), artery, & vein  Incisive foramen – in maxilla – carries nasopalatine nerve    

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http://en.wikipedia.org/wiki/Cranial_nerves#Thirteen_cranial_nerves.3F CN CN Name Nuclei Site of exit from skull # I Olfactory Anterior Olfactory Cribiform plate (ethmoid bone) II Optic Lateral Geniculate Optic foramen III Oculomotor Edinger-Westphal Superior orbital fissure Occulomotor IV V

Trochlear Trigeminal V1 Ophthalmic V2 Maxillary

Trochlear Mesencephalic, Main Sensory, Spinal, and Trigeminal Motor

V3 Mandibular

VI VII

Abducens Facial

VIII IX

Vestibulocochlear Glossopharyngeal

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Vagus

Superior orbital fissure Superior orbital fissure Foramen rotundum Foramen ovale

Abducens Facial, Solitarius (Gustatory), Salivatory Vestibular, Cochlear Ambiguus, Inferior Salivatory, Solitarius

Superior orbital fissure Internal auditory meatus

Ambiguus, Solitarius, Dorsal Motor

Jugular foramen

Internal auditory meatus Jugular foramen

Functions (M= motor; S = sensory) S = smell S = vision M = levator palpebrae superioris, medial, superior, inferior, inferior oblique, ciliary m. (lens), sphincter m. (pupil) M = superior oblique m. S = cornea, skin of nose, forehead, scalp S = nasal cavity, palate, Mx teeth, skin of cheek, upper lip S = tongue, Mn teeth, Mn, skin of chin, floor of mouth, TMJ M = mastication mm., tensors, anterior digastric, & mylohyoid M = lateral rectus m. S = taste (anterior 2/3) M = facial expression mm., lacrimation, salivation S = hearing, balance M = stylopharyngeus muscle (Only muscle it gets) S = taste (posterior 1/3), pharynx, middle ear, carotid sinuses M = muscles of pharynx & larynx (Ambiguus) M = smooth m. of thoracic & abdominal organs (Dorsal motor) S = taste (epiglottis) (Solitarius)

XI

Accessory

XII

Hypoglossal

Ambiguus, Spinal Accessory Hypoglossal

Jugular foramen

S = thoracic & abdominal organs (viscera) M = trapezius m. & SCM m.

Hypoglossal canal

M = intrinsic & extrinsic tongue mm.

CN IX CN X

Parasympathetic Nuclei & Ganglia by Cranial Nerve Ganglion Effector Ciliary G. Pupillary sphincter m. – meiosis Ciliary m. – accomodation Superior Salivatory N. Pterygopalatine G. Lacrimal gland & nasal cavity/nose – secretion Submandibular G. Submandibular & sublingual glands – secretion Inferior Salivatory N. Otic G. Parotid gland – secretion Dorsal Motor N. of Vagus *None* Viscera of thorax & abdomen

Ganglion Ciliary

Location Lateral to optic n.

Pterygopalatine

Pterygopalatine fossa

Submandibular

On hyoglossus m.

Otic

Below foramen ovale

Cranial Nerve CN III CN VII

Nucleus Edinger-Westphal N.

Autonomic Ganglia – PS & Symp fibers PS Fibers Symp Fibers PreG: CN III (inferior division) Internal carotid plexus PostG: Short ciliary nn. PreG: CN VII, greater petrosal n., & nerve of pterygoid canal PostG: Branches of V2,then V1 PreG: CN VII (Chorda tympani) PostG: Lingual n. PreG: CN IX & lesser petrosal n. PostG: Auriculotemporal n.

Internal carotid plexus Deep petrosal n. Plexus on facial artery Plexus on middle meningeal artery

Chief Distribution PS – Ciliary m. & sphincter pupillae Symp – Dilator pupillae & tarsal mm. Lacrimal gland & glands in palate & nose Submandibular & sublingual glands Parotid gland

CRANIAL NERVES - CN V, VII, IX, X are branchiomeric (nonsomitic) in origin because they originate from the branchial arches - Olfactory (CN I) o Exits Cribiform plate of ethmoid bone o Enters nasal canal for smell o Fracture of the cribiform plate typically results in loss of sense of smell - Optic nerves (CN II) o Arise from axons of the ganglion cells of the retina which converge at the optic disk o Optic foramen (optic canal):  Area where nerve enters the cranial cavity through the sphenoid bone o Optic disc (aka optic papilla):  Area where optic nerve exits eye  Made up of nerve cells  Small blind spot on surface of the retina – no rods or cones  Located ~3mm to nasal side of the macula  Only part of retina which contains no photoreceptors  Optic tracts consists of axons from ganglion cells  Consists of axons of ganglion cells exiting the retina to form the optic nerve • The axons are accompanied by the central artery & vein of the retina o After exiting eyes, optic nerves meet at the optic chiasm (in the floor of the diencephalon) o From optic chiasm, axons that perceive the left visual field form the right optic tract & vice-versa  Fibers that arise from the nasal hemiretinas decussate & contribute to the contralateral optic tract o Optic nerve fibers from the nasal side cross the midline and enter the optic tract of the other side by way of the optic chiasma  Fibers arising from the temporal hemiretinas remain ipsilateral  Optic tract fibers synapse in the lateral geniculate nuclei w/ geniculocalcarine fibers (optic radiations) that terminate on the banks of the calcarine sulcus in the primary visual cortex (Brodmann’s area 17) of the occipital lobe  So, the right visual field is interpreted in the left hemisphere of the brain & vice versa o Central artery of the retina (branch of ophthalmic artery), pierces the optic nerve & gains access to the retina by emerging from the center of the optic disc - Oculomotor nerve (CN III) o Supplies: medial, superior, & inferior recti; inferior oblique; & levator palpebrae superioris o Sends pregangl fibers to ciliary ganglion o Post gang fibers leave the ganglion in the short ciliary nerves to supply the sphincter pupillae & the ciliary muscle

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Oculomotor nerve (CN III), trochlear nerve (CN IV) & abducens nerve (CN VI) and ophthalmic (V div 1) all exit the cranium through the superior orbital fissure. They innervate the extrinsic ocular muscles, resulting in movement of the eyeball Trochlear nerve (CN IV): o Supplies the superior oblique muscle o Smallest cranial nerve o Only cranial nerve that emerges from dorsal aspect of the brainstem Trigeminal nerve (CN V): o Exits inferolateral PONS as a sensory & motor root o Largest of 12 cranial nerves o Larger sensory root enters the trigeminal (semilunar, gasserian) ganglion in the middle cranial foss, Embeds in Meckel’s CAVE o Three sensory divisions of the nerve arise from the ganglion & leave the cranial cavity through foramina in the sphenoid bone o Smaller motor root passes under the ganglion & joins the mandibular division as it exists through the foramen ovale Semilunar ganglion (aka trigeminal or gasserian ganglion) o Large, flattened, sensory ganglion of the trigeminal nerve o Lies close to cavernous sinus in the middle cranial fossa o Ophthalmic division (V1):  Enters orbit through superior orbital fissure  Sensory innervation to eyeball, tip of nose, skin on face above eyes  Three branches: lacrimal, frontal, & nasociliary o Maxillary division (V2):  Passes through foramen rotundum  Sensory innervation to midface (below eyes & above upper lip), palate, paranasal sinuses, & maxillary teeth o Mandibular division (V3):  Exits cranial cavity through foramen ovale  Motor innervation to tensor veli palatine, tensor tympani, muscles of mastication, and anterior belly of digastric & mylohyoid  Has no PS component at its origin:  Sensory innervation to: • Skin on Lower face, skin of mandible, lower lip & side of the head • TMJ (Auriculotemporal, and Masseteric and Posterior Deep Temporal), mandibular teeth, mucous MBs of cheek, floor of mouth, & anterior part of the tongue  Lingual nerve –branch of V3: • Descends deep to lateral pterygoid muscle, where it is joined by chorda tympani (branch of CN VII) which conveys pregang PS fibers to submandibular ganglion & taste fibers from anterior 2/3 of tongue • Supplies general sensation for anterior 2/3 of tongue, floor of mouth, & mandibular lingual gingiva • Submandibular duct has an intimate relation to the lingual nerve, which crosses it twice • Is directly on the lateral surface of the medial pterygoid muscle • If you cut lingual nerve after its junction w/ chorda tympani, pt loses taste & tactile sense to anterior 2/3 of tongue  Nerve to Masseter: • Passes through mandibular notch to enter muscle on medial surface • Also a branch of V3 • Carries a few sensory fibers to the anterior portion of the TMJ • Anterior portion of TMJ also supplied by branches of the posterior deep temporal nerve (branch of V3)  Auriculotemporal nerve: • Arises from posterior division of V3 • Provides posterior sensory innervation to TMJ o Pain (TMJ pt) is transmitted in the capsule & periphery of the disk by the auriculotemporal nerve • Pain from a fractured mandible • The joint only sends sensory information – it does not receive motor innervation (the muscles do, duh!) • Carries some secretory fibers from the otic ganglion to the parotid gland (from CN IX) • Referred pain from the TMJ to skin over the parotid region & side of head is based on the distribution of the auriculotemporal n. TMJ o Innervated by: (Think of the nerves as a MAP of the TMJ)  Nerve to the masseter (anterior portion) V3  Auriculotemporal (Primary) V3  Posterior deep temporal nerve (anterior portion) V3 CN III, VII, IX use branches of CN V to distribute their preganglionic PS to the PS head ganglia Abducens (CN VI): o Supplies the lateral rectus of the eye o NOT found within the walls of the cavernous sinus (III, IV, V1, and V2 are) – actually within the C sinus itself. Facial nerve (CN VII):

Contains sensory neurons that originate from taste buds on anterior 2/3 of tongue  The cell bodies are located in the geniculate ganglion, which lie in the facial canal, in the inner ear o Associated with the second pharyngeal arch o Innervates the facial muscles w/ motor fibers o Supplies the Mimetic muscles (LIKE a MIME, facial expression) o Lacrimal gland & salivary glands w/ PS fibers o Anterior tongue w/ taste fibers o Originates in the pons o Traverses the facial canal of the temporal bone & exits the stylomastoid foramen o Also contains PS fibers to sublingual & submandibular glands (via submandibular ganglion) o Facial nerve function:  Motor innervation: • Muscles of facial expression • Posterior belly of digastric muscle & stylohyoid muscle – after CN VII emerges from stylomastoid foramen • Stapedius muscle w/in the middle ear • Damage just after it left stylomastoid foramen would cause loss of innervation to facial muscles (orbicularis oculi m.) • Which structure innervates the orbicularis oculi?  Temporal and zygomatic branches of CN VII  Sensory: proprioceptive innervation: from the same muscles listed for motor innervation  Secretomotor: PS innervation. Secretion of tears from the lacrimal gland & salivation from the sublingual & submandibular glands  Special sensory: taste impulses (sweet sensation) from the taste buds on the anterior 2/3 of tongue, floor of mouth, & palate o Bell’s Palsy  Damage to the facial nerve or its branches may cause weakness or paralysis of facial muscles  Peripheral ipsilateral facial paralysis  Inability to close eye on affected side  Complete destruction of the facial nucleus itself OR its branchial efferent fibers (facial nerve proper) paralyzes all ipsilateral facial muscles  Upper motor neuron  Can wrinkle forehead (Inability to smile – he can still wrinkle forehead because upper face gets innervation from the BOTH sides of the brain (See Pic)  Lower motor neuron lesion (i.e. Facial Nucleus Destruction) Complete facial paralysis (Inability to smile OR wrinkle forehead) PS innervation controlling salivation originate in facial & glossopharyngeal nerves Chorda tympani o Emerges from a small canal in posterior wall of tympanic cavity & crosses medial surface of tympanic MB o Joins lingual nerve in the infratemporal fossa Geniculate ganglion: o Located w/in the facial canal (petrous portion of temporal bones) o Contains sensory neurons via chorda tympani of CN VII (innervates taste buds on anterior 2/3 of tongue) o Greater petrosal nerve:  Parasymp secretomotor branch of CN VII and general visceral afferent fibers • No sympathetic fibers or general somatic efferents  Also described as the parasympathetic root of the pterygopalatine ganglion  Arises from the geniculate ganglion  Carries PS preG fibers to pterygopalatine ganglion • Exits cranial cavity through foramen lacerum • Enters pterygoid canal after joining w/ deep petrosal nerve to form the nerve of the pterygoid canal o Deep petrosal nerve is carrying postG S from the superior cervical ganglion o Both form the nerve of the pterygoid canal (Vidian’s) • In pterygopalatine fossa, the nerve of the pterygoid canal terminates in the pterygopalatine ganglion o

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• PS pre-ganglionics from greater petrosal nerve synapse w/ post-ganglionics here • S (already post-ganglionics) just pass on through the ganglion w/out synapsing  Post-ganglionic autonomics – distributed to lacrimal gland & glands of mucous MB of nasal cavity, pharynx, & palate  Also transmits taste centrally from palate through palatine nerves • These taste fibers also necessarily pass through the pterygopalatine ganglion & nerve of the pterygoid canal to reach the greater petrosal nerve on their way to the tractus & nucleus solitarius in the pons o Lesser petrosal nerve:  Pregang PS to the otic ganglion  parotid gland (via auriculotemporal nerve V3) • NOTE: the postG PS cell bodies to the parotid gland are found in the otic ganglion • Stimulation of lesser petrosal nerve causes secretion by parotid gland • Tympanic & lesser petrosal branches of CN IX supply preganglionic PS secretomotor fibers to the otic ganglion o Preganglionic fibers leave CN IX as the tympanic nerve (SEE MIDDLE PIC)  Tympanic nerve enters middle ear cavity & participates in formation of the tympanic plexus (on the medial Wall), where chorda tympani runs from posterior wall across lateral wall (aka medial surface of Tympanic MB) o It reforms as the lesser petrosal nerve, leaves cranial cavity through foramen ovale, & enters otic ganglion  Diminshed salivary gland production from the parotid due to MIDDLE EAR damage has most likely affected the Lesser Petrosal Nerve (NOT the auriculotemporal) Glossopharyngeal nerve (CN IX): o Originates from anterior surface of the medulla oblongata along w/ CN X & CN XI o Passes laterally in posterior cranial fossa & leaves skull through the jugular foramen o Splits the Superior and Middle Constrictors to enter the oral cavity o Supplies sensation (including pain) to pharynx & posterior 1/3 of tongue o Innervates derivatives of the 3rd branchial arch o Innervates stylopharyngeus muscle (the only muscle supplied by CN IX)  Landmark for locating CN IX – as CN IX enters pharyngeal wall, it curves posterior around the lateral margin of the muscle o Cell bodies of these sensory neurons are located in Superior & Inferior ganglia of this nerve  Cell bodies of pain fibers in CN IX are found in the superior ganglion of CN IX o Descends through upper part of neck along w/ internal jugular vein & internal carotid artery  Reaches posterior border of the stylopharyngeus muscle – supplies it w/ somatic motor fibers o Caries 1° afferent neurons that cause the gag reflex (innervates mucous MBs of the fauces) o ***NOTE: CN III, VII, IX, & X all carry pre-gang PS fibers o Visceral sensory branches of CN IX:  Lingual • Terminal branch of CN IX to posterior 1/3 of tongue conveying general sensation & taste to circumvallate papillae • Also carries some secretomotor fibers to the glands  Pharyngeal • Distributed to mucous MB of the pharynx – sensory limb of the gag reflex  Carotid sinus nerve • To carotid sinus (baroreceptor) & carotid body (chemoreceptor) o Remember Sinus gets it from IX, but the whole BODY gets it from IX and X, aortic arch only from X Otic ganglion: o Pregang PS cell bodies originate in the Inferior Salivatory nucleus o Small PS ganglion, functionally associated w/ CN IX o Situated below foramen ovale; medial to V3 o Tympanic & lesser petrosal branches of CN IX supply preganglionic PS secretomotor fibers to the otic ganglion  Preganglionic fibers leave CN IX as the tympanic nerve • Tympanic nerve enters middle ear cavity & participates in formation of the tympanic plexus • It reforms as the lesser petrosal nerve, leaves cranial cavity through foramen ovale, & enters otic ganglion o Postgang PS fibers leave the ganglion & join the auriculotemporal nerve→jump off at the parotid gland Vagus Nerve (CN X): o Leaves brain from medulla & exits cranial cavity through jugular foramen o Contains PS pre-ganglionic fibers to thoracic & abdominal viscera o Descends in neck in the carotid sheath behind the internal & common carotid arteries & internal jugular vein o Both R & L Va-Goose trunks pass through posterior mediastinum on the esophagus & enter abdominal cavity w/ the esophagus o In the lower thorax, the esophageal branches of the right vagus branches are found mainly on the posterior esophagus  Just make the right hand turn on the wheel – the left vagus goes to the anterior o Supplies viscera of neck, thorax, & abdomen to the left colic (splenic) flexure of large intestine  Abdominal viscera below left colic flexure, & pelvis & genitalia supplied w/ pregang PS fibers from pelvic splanchinc nerves o Vasomotor sympathetic fibers are thought to end on BVs

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Possesses Two Sensory Ganglia:  Superior ganglion (lies on nerve w/in jugular foramen) • Meningeal – supplies dura mater • Auricular – supplies auricle, external auditory meatus  Inferior ganglion (lies on nerve just below the jugular foramen) • Pharyngeal o Forms pharyngeal plexus o Supplies:  Pharyngeal muscles, except stylopharyngeus (CN IX)  Soft palate muscles, except tensor veli palati (V3) • Superior laryngeal, divides into: o 1) Internal laryngeal – travels w/ superior laryngeal artery & pierces thyrohyoid MB  Supplies mucous MB of larynx above vocal folds o 2) External laryngeal – travels w/ superior thyroid artery & supplies cricothyroid muscle Sensory Portion of CN X:  Somatic sensory fibers – to skin of the ear • Cell bodies in the superior ganglion of CN X (somatic sensory nucleus) • Axons enter spinal tract & nucleus of CN V  Visceral sensory fibers – to pharynx, larynx, & thoracic & abdominal viscera to the left colic flexure (hunger pangs) • Cell bodies in inferior ganglion of CN X (visceral sensory nucleus) • Axons enter tractus & nucleus solitarius  Visceral sensory fibers – to epiglottis (taste) • Cell bodies in inferior ganglion • Axons enter tractus & nucleus solitarius Motor Portion of CN X:  Branchiomeric motor fibers – to skeletal muscle derived from visceral arch muscle in larynx, upper esophagus & pharynx • Cell bodies of these motor neurons are in nucleus ambgiuus  Visceral motor fibers – to smooth muscles & glands of the organs of the neck, thorax, & abdomen • These are the PS preganglionic fibers w/ cell bodies in dorsal motor nucleus of vagus o One Q asked about the preG PS fibers of the duodenum – these are found in the dorsal motor nucleus of vagus Left vagus nerve:  Enters thorax in front of the left subclavain artery & behind the left brachiocephalic vein  Then crosses left side of the aortic arch & is itself crossed by the left phrenic nerve  Then passes behind the left lung, forms the pulmonary plexus, & continues to form the esophageal plexus  Enters abdomen in front of the esophagus through the esophageal hiatus of the diaphragm as the anterior vagal trunk Right vagus nerve:  Crosses anterior surface of the right subclavian artery & enters thorax posterolateral to the brachiocephalic trunk, lateral to the trachea, & medial (& just posterior) to the azygos vein  Passes posterior to root of the lung, contributing to the pulmonary plexus  Contributes to the esophageal plexus  Enters abdomen behind the esophagus through the esophageal hiatus of the diaphragm as the posterior vagal trunk R&L vagus nerves lose their identity in the esophageal plexus  At lower end of the esophagus, branches of the plexus reunite to form the anterior vagal trunk (anterior gastric nerve) • Anterior vagal trunk can be cut (vagotomy) to reduce gastric secretion Right recurrent laryngeal nerve  Arises from right vagus nerve in neck  Hooks around subclavian artery & passes up/backwards behind artery & ascends in groove between trachea & esophagus (tracheoesophageal groove) (Plate 554 Clemente’s)  Innervates: • All muscles of the larynx (except cricothyroid – supplied by external laryngeal branch of superior laryngeal nerve) o The external laryngeal branch runs with superior thyroid artery to the cricothyroid • Mucous MB of larynx below the vocal folds • Mucous MB of upper part of the trachea  Comes in contact w/ thyroid gland & comes into close relationship w/ inferior thyroid artery Left recurrent laryngeal nerve  Crosses arch of the aorta, hooks around ligamentum arteriosum, & ascends in groove between trachea & esophagus  Arises from left vagus  Innervates: • Same muscles as right recurrent, but on left side A few cardiac branches arise from CN X & enter cardiac plexus  When BP goes up, then these branches increase firing

 These are pre-gang PS nerves  Innervate heart mucle & conducting system (SA node, etc.) - Accessory Nerve (CN XI): o Innervation to the SCM and Trapezius - Hypoglossal Nerve (CN XII): o Motor nerve supplying all intrinsic & extrinsic muscles of the tongue (except palatoglossus – CN X and Genioglossus C1 via XII) o Leaves skull through hypoglossal canal medial to carotid canal & jugular foramen o Passes above hyoid bone on the lateral surface of hyoglossus muscle deep to the mylohyoid muscle (Between Hyoglossus and mylohyoid) – pp 565 ECA 2nd ed. o Landmark  Loops around occipital artery(Clemente 444)& passes between the external carotid artery & internal jugular vein o Soon after it leaves the skull through the hypoglossal canal. it is joined by C1 fibers from cervical plexus  TO then supply Genioglossus, Geniohyoid, Thyrohyoid o Unilateral lesions – result in deviation of protruded tongue toward the affected side – due to lack of function on diseased side o LMN Injury of CN XII eventually produces paralysis & atrophy of tongue on affected side w/ tongue deviated to the affected side  Dysarthria (inability to articulate) may also be found o NOTE: if genioglossus muscle is paralyzed, tongue has tendency to fall back & obstruct oropharyngeal airway – suffocation risk - Cranial Nerve lesions: o CN V (motor) – jaw deviates TOWARD side of lesion o CN X – uvula deviates AWAY from side of lesion o CN XI – head turns TOWARD side of lesion o CN XII – tongue deviates TOWARD side of lesion ************************************************************************** - Sympathetic ganglia: o Sympathetic trunks – two long chains of symp ganglia on either side of vertebral column that extend from base of skull to coccyx • Damage to the sympathetic trunk causes Horner’s Syndrome  Lie close to vertebral column & end below by joining to form a single ganglion – the ganglion impar (unpaired)  Sympathetic ganglia are located at intervals on each sympathetic trunk alongside vertebral column • Generally there are 3 cervical, 12 thoracic, 4 lumbar, & 4 sacral  Gray rami connect sympathetic trunk to every spinal nerve  White rami are limited to the spinal cord segments between T1 & L2  Cell bodies of visceral efferent fibers (in visceral branches of the sympathetic trunk) – located in lateral horn of spinal cord (Intermediolateral cell column).  Cell bodies of visceral afferent fibers – located in dorsal root ganglia o Sympathetic nerves (Splanchics) arise from thoracic sympathetic ganglia (T5-T12) – they all pass through diaphragm o PreG Symp fibers may pass through ganglia on thoracic part of sympathetic trunk w/out synapsing  These myelinated fibers form the splanchnic nerves: • Greater – symp fibers from T5-T9 pierce diaphragm & synapse w/ excitor cells in the ganglia of celiac plexus o Nerves consist primarily of preganglionic visceral efferent fibers o The thoracic splanchnic nerves to the celiac ganglion consist predominantly of preG visceral efferents o PostG fibers arise from excitor cells in celiac plexus & are distributed to smooth muscle & glands of viscera o Travels just posterior to the azygos vein • Lesser – symp fibers from T10-T11 pierce diaphragm & synapse w/ excitor cells in aorticorenal ganglion • Least – symp fibers from T12 pierce diaphragm & synapse w/ excitor cells in ganglia of the aorticorenal plexus  The fibers from the thoracic splanchnics (T5-12) and the lumbar splanchnics synapse largely in 3 ganglia: • 1) Celiac ganglion • 2) Superior Mesenteric ganglion • 3) Inferior Mesenteric ganglion o Some nerve fibers go even more inferior to the superior hypogastric plexus to provide sympathetic innervation to the pelvic viscera o NOTE: PS innervation of the upper 2/3 of the abdominal viscera comes via the vagus nerve which goes through the celiac plexus w/o synapsing like the sympathetics do  The remaining inferior portions come by way of the parasympathetics from S2, S3, S4 via pelvic splanchnics o Cervical Ganglia:  Sympathetic innervation to head & neck structures is distributed via the blood vessels (NOT CN III, VII, IX, X)  Superior cervical ganglion • Uppermost & largest lies between internal carotid artery & internal jugular vein • Most of postG sympathetic fibers that go to head region have their cell bodies located here o EX: The postG sympathetic fibers to the vessels of the SM gland arise from cells in the superior cervical ganglion o This is where the preG and postG sympathetic fibers of the cervical region synapse o Cell bodies of sympathetic fibers in the nerve of the pterygoid canal come from the superior cervical ganglion

Postganglionic sym cell bodies that provide innervation to the submandibular gland is located in superior cervical ganglion • Some fibers go to the upper 3 to 4 cervical nerves  Middle cervical ganglion • Fibers to the cervical nerves C5 & C6 • Small, located at level of cricoid cartilage • Related to the loop of the inferior thyroid artery  Inferior cervical ganglion • Fibers to spinal nerves C7, C8, & T1 • Most commonly fused to first thoracic sympathetic ganglion to form a stellate ganglion Cervical plexus: o Cervical nerves C1-C4 contribute motor fibers to plexus o Motor nerves are branches of ansa cervicalis (loop formed by C1-C3) o Positioned deep on side of the neck, lateral to the 1st four cervical vertebrae o An important branch of each cervical plexus is the phrenic nerve (C3-C5) – supplies diaphragm o Provides cutaneous innervation to skin of the neck, shoulder & upper anterior chest  Supraclavicular nerves innervate skin over the shoulder  Transverse cervical nerve provides sensory innervation to anterior/lateral parts of the neck o Provides motor innervation to infrahyoid (strap) muscles (except for the thyrohyoid—C1 via XII & to the geniohyoid muscle) o Gives rise to the first 2 of 3 roots contributing to the phrenic nerve that innervates the diaphragm (C3, 4, 5) o

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Brachial plexus (C5-T1) o Formed in posterior triangle of the neck o Extends into axilla, supplying nerves to the upper limb o Axillary sheath contains the Cords of the brachial plexus and the axillary artery and vein (NOT subclavian artery???)  Sheet music contains Cords o Think Randy Travis Drinks Cold Beer o Roots  Trunks  Divisions  Cords  Branches  (Question: What is terminal portion of brachial plexus called?) o 5 Roots o 3 Trunks:  Superior C 5,6  Middle C 7  Inferior C8, T1 o Each splits into anterior and posterior division o 3 Cords:  Lateral C5,6,7  From Superior and Middle Roots • Lateral pectoral nerve C5,6,7 • Musculocutaneous nerve C 5,6,7 • **Median nerve (forms from the medial & lateral cords) C5-T1 

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Posterior C5,6,7,8,T1  From All 3 Roots • Axillary nerve C5,6 • Radial nerves C5-T1

Medial (C8, T1)  From Inferior • Medial pectoral nerve C8,T1 • Ulnar nerve C8,T1 – ulnar nerve is a terminal branch of the medial cord o Ulnar nerve is most sensitive at the elbow (not wrist, hands) – think funny bone • **Median nerve (forms from the medial & lateral cords) C5-T1 o Brachial artery runs adjacent to and parallel with the median nerve in the arm Branches  Think from Back to front to Medial  ARMMU Anteriors  **Arm & Forearm Flexors • Musculocutaneous – biceps, brachialis, coracobrachialis mm. • Median – forearm flexors, thenar mm., radial lumbricals • Ulnar – Ulnar flexors, adductor pollicis, hypothenar mm., interossei, lumbricals 4-5 Posteriors  **Arm & Forearm Extensors (posterior of the arm/forearm)

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Radial – both arm & forearm extensors o (triceps, brachioradialis, supinator, extensors of wrist/fingers)

Hand  Thenar muscles: • Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis • Innervated by the median nerve (don’t get clowned by the radial nerve) • Numbness of Forefinger and thumb caused by damage to the Median nerve  Hypothenar muscles: (all are “____ digiti minimi”) • One Half LOAF  One and half Lumbricals, Opponens d.m., Abductor d.m., Flexor d.m. • Innervated by Ulnar nerve  The lateral two lumbricals are also innervated by the median nerve  The rest of the intrinsic muscles of the hand are innervated by the ulnar nerve (i.e. interosseoi)

Lumbar plexus: L1-L4 o Formed in psoas muscle o Supplies lower abdomen & parts of the lower limb o Main branches are the femoral & obturator nerves Sacral plexus: L4-L5 & S1-S4 o Lies in posterior pelvic wall in front of piriformis muscle o Supplies lower back, pelvic, & parts of thigh, leg, & foot o Main branches are the sciatic (largest nerve in body), gluteal, & pelvic splanchnic nerves Dermatome: o Area of skin supplied by a single spinal nerve o *Supplied by either cranial or spinal nerves o Cranial nerves  All 3 divisions of CN V supply the skin of face, anterior scalp (V1) & ear (V3) • The ear receives additional innervation from CN VII, IX, & X  All but one of the spinal nerves’ anterior & posterior primary divisions innervate the remaining dermatomes of the body • The greater occipital nerve (C2) supplies posterior scalp because C1 usually does not supply a dermatome  No overlapping innervation of cranial dermatomes o Spinal (peripheral) nerve innervation of the skin (cutaneous innervation):  Usually differs from cranial nerve skin innervation because ventral primary divisions of spinal nerves form plexuses • Allows multiple spinal nerves to constitute a peripheral nerve o EX: C5-C7 form the musculocutaenous nerve • Spinal nerve dermatomes overlap 50% • Must anesthetize T4-T6 to block feeling in T5 dermatome

Functional Components of Nerves  Spinal Nerves  ***Only contain 4 of 7 functional components (just the “General”, not “Special” components)  Efferent  GVE – smooth muscle, cardiac muscle, glands • PreG S: C8→L2 w/ cell bodies located in the intermediolateral nucleus • PreG PS: S2→S4 w/ cell bodies located lamina VII (analagous to the intermediolateral nucleus)  GSE – skeletal muscle – arise from alpha & gamma motor neurons of lamina IX (anterior horn)  Afferent (all arise from DRGs)  GVA – sensory info from the viscera (although technically not a part of the ANS)  GSA – exteroceptive & proprioceptive sensation • Exteroceptive – touch, pain, temp

• Proprioceptive – joints, muscle, tendons, fascia  Cranial Nerves  Afferent  GSA – see above  *SSA – Vision, Hearing & Equilibrium  GVA – see above  *SVA – Olfaction & Taste (Southern Virginia is OuT there!!!) • Special visceral afferent fibers for taste are conveyed in VII, IX, & X  Efferent  GSE – skeletal muscle from myotomes  GVE – PreG PS (no Symp): CN III, VII, IX, X  *SVE (Brachial Arches) • CN V – mastication – from motor nucleus of V • CN VII – facial expression – from facial nucleus • CN IX & X – larynx, pharynx – from nucleus ambiguus • CN XI – trapezoid (lift shoulders), SCM (turn head) The ENTIRE Cranial Nerve MAP  CN I (Olfactory Nerve)  Special Visceral Afferent  Enter/exit cribriform plate  Conveys information from olfactory epithelium  CN II (Optic Nerve)  Special Somatic Afferent (Special Visceral Afferent according to Moore pg. 644)  Enter/exit optic canal  Conveys information from retina  CN III (Occulomotor Nerve)  Part 1 - General Somatic Efferent  Enter/exit superior orbital fissure within annulus tendinus Superior Division  Innervates superior rectus muscle  Innervates levator palpebrae superioris muscle Inferior Division  Innervates inferior rectus muscle  Innervates medial rectus muscle  Innervates inferior oblique muscle 

Part 2 – General Visceral Efferent (PARASYMPATHETIC PART)  Carries preganglionic parasympathetic fibers along inferior division to ciliary ganglion  Fibers synapse in ciliary ganglion  Short ciliary nerves carry postganglionic parasympathetic fibers from ciliary ganglion to innervate sphincter of pupil and ciliaris muscle  Ciliary ganglion also carries 1) postganglionic sympathetic fibers along short ciliary nerves to blood vessels of eyeball and the tarsals, 2) Afferent fibers from nasociliary nerve (CN5 V1)

 CN IV (Trochlear Nerve)  General Somatic Efferent  Enter/exit superior orbital fissure  Innervates superior oblique muscle  CN V (Trigeminal Nerve)  Exits the PONS  V1 (Opthalmic Nerve)  General Somatic Afferent  Enter/exit superior orbital fissure  Sensory nerve with 3 main branches Frontal Nerve (Branch 1)

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Enter/exit superior orbital fissure above annulus tendinus Supraorbital Nerve ♦ Exit supraorbital foramen ♦ Innervates frontal sinus, conjunctiva upper eyelid, skin of forehead Supratrochlear Nerve ♦ Exit on medial side of supraorbital nerve ♦ Innervates skin in middle of forehead to hairline

Nasociliary Nerve (Branch 2)  Enter/exit superior orbital fissure within annulus tendinus Infratrochlear Nerve ♦ Exits of medial wall of orbit above upper eyelid ♦ Innervates skin and conjunctiva of upper eyelid Anterior Ethmoid Nerve ♦ Courses w/ anterior ethmoid artery (ophthalmic artery) through anterior ethmoid foramen ♦ Innervates anterior ethmoid sinuses and anterosuperior part of nasal mucosa on both septum and lateral wall of nasal cavity ♦ Terminal branch is External Nasal Nerve, innervates skin on dorsum and tip of nose Posterior Ethmoid Nerve ♦ Courses w/ posterior ethmoid artery (ophthalmic artery) through posterior ethmoid foramen ♦ Innervates posterior ethmoid sinuses and sphenoid sinuses Long Ciliary Nerves (2) ♦ Innervates (sensory to) iris, cornea, and ciliary body ♦ Carry postganglionic sympathetic fibers to the dilator of the pupil Sensory Root to Ciliary Ganglion ♦ Sensory fibers to eyeball from nasociliary nerve pass through ciliary ganglion and course w/ short ciliary nerves (CN 3) Lacrimal Nerve (Branch 3)  Enter/exit superior orbital fissure above annulus tendinus ♦ Gland is in the outer lateral side  Courses forward in lateral part of orbit to the lacrimal gland  Carries postganglionic parasympathetic fibers (secretomotor) from pterygopalatine ganglion via zygomaticotemproal nerve (CN5 V2) from greater petrosal nerve (CN7) ♦ [CN V1 via CN V2 via CN7]  Carries postganglionic sympathetic fibers (vasoconstrictive) from pterygopalatine ganglion via zygomaticotemproal nerve (CN5 V2) from deep petrosal nerve (Superior Cervical Ganglion) ♦ [CN V1 via CN V2 via Superior Cervical Ganglion] 

V2 (Maxillary Nerve)  General Somatic Afferent  Enter/exit foramen rotundum then runs anterolaterally through pterygopalatine fossa  If anesthesia was injected into the pterygopalatine fossa, then V2 would be anesthetized  Within fossa gives rise to 3 branches: Zygomatic Nerve (Branch 1)  Arises in floor of orbit through inferior orbital fissure  Innervates skin over zygomatic arch and anterior temporal region ♦ Best described as sensory branches of maxillary division of V  Gives rise to 2 terminal braches: Zygomaticofacial Nerve ♦ Exit zygomaticofacial foramen Zygomaticotemporal Nerve

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Exit zygomaticotemporal foramen Carries postganglionic parasympathetic fibers (secretomotor) to lacrimal nerve (CN5 V1) from pterygopalatine ganglion via zygomaticotemporal nerve (CN5 V2) from greater petrosal nerve (CN7) [CN5 V1 via CN5 V2 via CN7] Carries postganglionic sympathetic fibers (vasoconstrictive) to lacrimal nerve (CN5 V1) from pterygopalatine ganglion via zygomaticotemporal nerve (CN5 V2) from deep petrosal nerve (Superior Cervical Ganglion) [CN5 V1 via CN5 V2 via Superior Cervical Ganglion]

Ganglionic Branches (2) Supporting Pterygopalatine Ganglion (Branch 2 and 3)  Convey general sensory fibers from maxillary nerve that pass through ganglion  (Note: all the braches of the pterygopalatine ganglion are mixed nerves with General Somatic Afferent fibers from the maxillary nerve, and General Visceral Efferent fibers from the nerve of the pterygoid canal [see below])  Pterygopalatine ganglion gives off numerous braches: Greater Palatine Nerve ♦ Innervates gingivae, mucous membranes, glands of hard palate Lesser Palatine Nerve ♦ Innervates gingivae, mucous membranes, glands of soft palate Nasopalatine Nerve ♦ Courses through sphenopalatine foramen along posterior half nasal septum (along with the Sphenopalatine artery)  NOTE: The spenopalatine foramen is the hole on the MEDIAL wall of the pterygopalatine fossa  In other words it is the direct connection with the nasal region and the Ganglion region of V2 ♦ Innervates mucosa in this region then dives down through incisive canal ♦ Innervates mucous membranes and gland of anterior part of hard palate Nerve of the Pterygoid Canal ♦ General Visceral Efferent ♦ Carries preganglionic parasympathetic fibers from CN7 via greater petrosal nerve, these are secretomotor to mucosa and glands and synapse in ganglion ♦ Carries postganglionic sympathetic fibers from Superior Cervical Ganglion via deep petrosal nerve, these are vasoconstrictive to mucosa and glands, do not synapse Posterior Superior Lateral Nasal Nerve ♦ Innervates mucosa on superior half of lateral wall of nasal septum Posterior Inferior Lateral Nasal Nerve ♦ Innervates mucosa on inferior half of lateral wall of nasal septum  

Maxillary nerve then leaves pterygopalatine fossa through inferior orbital fissure Henceforth it is known as the Infraorbital nerve (CAREFUL, you’re still in bones)

Infraorbital nerve  It then gives rise to 3 large sensory branches:  Innervates the upper lip Posterior Superior Alveolar Nerve  Sensory innervation to maxillary molars  Doesn’t get MB of M1 Middle Superior Alveolar Nerve  Sensory innervation to maxillary molars and premolars Anterior Superior Alveolar Nerve  Sensory innervation to premolars, a branch dives through the incisive canal and emerges as the Incisive Nerve to supply the maxillary canines and incisors  (Note: nasopalatine nerve also courses through incisive canal)  

Maxillary Nerve then continues along floor or orbit through infraorbital sulcus It dives down through the infraorbital canal and emerges through the infraorbital foramen and serves to innervate (sensory to) the skin of the cheek, lower lid, lateral side of nose and upper lip

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Superior labial branches (skin over cheek and upper lip)

V3 (Mandibular Nerve)  Mixed nerve w/ General Somatic Afferent (sensory) and Special Visceral Efferent fibers (motor)  Enter/exit foramen ovale and enters infratemporal fossa  Divides into anterior and posterior trunks  Anterior trunk gives rise to: Long Buccal Nerve  Innervates skin and mucosa of the cheek, vestibule, and buccal gingiva adjacent to 2nd and 3rd molars  Pain from Swelling of the gingiva would be transmitted via the Buccal nerve Branches to Four of the Muscles of Mastication  Motor nerve to Masseter, Temporalis, Medial Pterygoid, Lateral Pterygoid muscles Branches to Additional Muscles (not sure if these branches from anterior trunk…)  Motor nerve to anterior belly of the digastric (accessory muscle of mastication), tensor veli palatini, tensor tympani, and the mylohyoid  

(Note: muscles of mastication and innervation derived from 1st pharyngeal gill arch)

Posterior trunk gives rise to: Auriculotemporal Nerve  Passes between neck of mandible and external acoustic meatus  Innervates skin anterior to ear and posterior temporal region  Pain from fractured mandible  Carries postganglionic PS fibers (secretomotor) from otic ganglion to the parotid salivary gland, these general visceral efferent fibers come to the otic ganglion via the lesser petrosal nerve (preganglionic parasympathethic) from CN 9 (see below)  Marker: middle meningeal artery passes between branches that make up auriculotemporal nerve – Plate 479 (Clemente’s Atlas) Inferior Alveolar Nerve  Enters mandibular foramen  Sensory innervation to mandibular teeth Mental Nerve ♦ Terminal branch of mandibular nerve ♦ Exits through mental foramen ♦ Innervates skin of chin, lower lip, mucosa of lower lip  Pt with dentures has caused pain in the inner vestibule or something  which nerve was irritated  Mental Nerve of the Mylohyoid ♦ Runs along the mylohyoid groove ♦ Motor nerve to Mylohyoid muscle (accessory muscle of mastication) Lingual Nerve  Enters mouth between medial pterygoid and ramus of mandible inferior to 3rd molar  Sensory innervation to anterior 2/3 of the tongue, floor of the mouth, lingual gingiva  Carries Special Visceral Afferent fibers via Chorda Tympani: Chorda Tympani ♦ Special Visceral Afferen(taste), General Visceral Efferent (salivary gland) ♦ Branch of CN VII, passes through middle ear over tympanic membrane ♦ Joins lingual nerve in infratemporal fossa ♦ Carries taste fibers to anterior 2/3 of the tongue ♦ Carries preganglionic parasympathetic fibers (secretomotor) to submandibular ganglion for the submandibular and sublingual salivary glands

 CN VI (Abducens Nerve)

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General Somatic Efferent Enter/exit superior orbital fissure Innervates lateral rectus muscle What muscles Abducts the eye?  Abducens (“Abductens”) Paralysis of lateral rectus muscle causes interference with?  Abduction of the eye

 CN VII (Facial Nerve)  Motor and sensory nerve, see Moore pgs. 658-660 (sensory for taste and from part of the external ear (Concha of auricle).  Supplies the Mimetic muscles (muscles of facial expression)  Consists of two roots  Smaller root has taste (Special Visceral Afferent), parasympathetic (General Visceral Efferent) and sensory (General Somatic Afferent) fibers  Larger root carries motor fibers to muscles from 2nd pharyngeal arch (Special Visceral Efferent)  Nerve enters internal acoustic meatus  Within facial canal it gives rise to: Greater Petrosal Nerve  (General Visceral Efferent)  Carries preganglionic parasympathetic fibers to pterygopalatine ganglion  Joins the deep petrosal nerve as it passes through cartilage of foramen lacerum • (Note: These two nerves form the nerve of the pterygoid canal)  After synapse, postganglionic parasympathetic fibers innervate lacrimal gland (See Above), and mucous glands of nasal cavity, palate, upper pharynx Nerve to Stapedius  (Special Visceral Efferent)  Innervates stapedius muscle in middle ear  Prevents excess movement of the stapes Chorda Tympani Nerve  Passes through middle ear over tympanic membrane  Joins lingual nerve in infratemporal fossa  Carries taste fibers to anterior 2/3 of the tongue (Special Visceral Afferent)  Carries preganglionic parasympathetic fibers (secretomotor) to submandibular ganglion for the submandibular and sublingual salivary glands (General Visceral Efferent)  (Note: Sensory fibers (General Somatic Afferent) to concha of auricle of external ear arise here)     

Larger motor root (Special Visceral Efferent) exits stylomastoid foramen Gives off motor braches to occipitalis and auricular muscles (via Posterior Auricular Branch) Gives off motor branches to posterior belly of the digastric and stylohyoid muscles Pierces parotid gland Gives off five terminal motor branches to muscles of facial expression: (TZBMC)  Two Zebras Broke My Coccyx Temporal Branch Zygomatic Branch Buccal Branch Mandibular Branch Cervical Branch

 CN VIII (Vestibulocochlear Nerve)  Special Somatic Afferent (Special Visceral Afferent according to Moore pg. 644)  Enter/exit internal acoustic meatus  Conveys equilibrium, balance (Vestibular fibers) and hearing (Cochlear fibers) information from inner ear  CN IX (Glossopharyngeal Nerve)  Motor (General Visceral Efferent and Special Visceral Efferent) and sensory (General Somatic Afferent and Special Visceral Afferent) nerve, see Moore pgs. 662-663  From Inferior Salivatory Nucleus  Goes to tympanic plexus as tympanic nerve, then turns into lesser petrosal nerve (carrying Pregang PS to the otic ganglion, which then sends Postgang PS to the parotid via the auriculotemporal (V3)  Enter/exit jugular foramen  Gives off two small branches:

Tympanic Nerve  Courses through middle ear  Forms tympanic plexus on promontory of middle ear  Provides sensory innervation (General Somatic Afferent) to the internal surface of the tympanic membrane • “Clogged ears” from pressure on the auditory tubes is sensed via CN IX (don’t get clowned by vestibulocochlear)  Reforms as the lesser petrosal nerve  Carries preganglionic parasympathetic fibers (General Visceral Efferent) to the otic ganglion to supply the parotid gland via the auriculotemporal nerve (CN5V3) (See Above) Carotid Branch  Special Visceral Afferent  Provides baroreceptor innervation to the carotid sinus    

Follows and gives motor innervation (Special Visceral Efferent) to Stylopharyngeus muscle (derived from 3rd pharyngeal arch) Gives of Pharyngeal Branch to Pharyngeal Plexus of nerves (CN9 and CN10), this gives sensory innervation (General Somatic Afferent) to the oropharynx Passes b/w superior and middle constrictor muscles to reach oropharynx Gives of two branches: Tonsilar Branch  General Somatic Afferent  Provides sensory innervation to the palatine tonsil Lingual Branch  Provides general sensory innervation (General Somatic Afferent) to posterior third of tongue  Provides taste fibers (Special Visceral Afferent) to posterior third of tongue

 CN10 (Vagus Nerve)  Motor and sensory nerve, see Moore pgs. 664-666  Enter/exit jugular foramen  Joins with cranial root of CN11  Enters carotid sheath and continues to root of the neck  Gives off multiple branches: Pharyngeal Branch  Innervation to pharyngeal constrictor muscles (Special Visceral Efferent), except cricopharyngeus, and pharyngeal longitudinal muscles, except stylopharyngeus (Note: pharyngeal muscles derived form 4th through 6th pharyngeal arches)  Provides general sensory innervation (General Somatic Afferent) to laryngopharynx  (Note: motor innervation is really cranial root CN11 via CN10) Superior Laryngeal Nerve  Divides into two terminal nerves: Internal Laryngeal Nerve ♦ Sensory (General Somatic Afferent) to root of tongue to vocal folds ♦ Carries preganglionic parasympathetic (General Visceral Efferent) to mucous membrane in same area External Laryngeal Nerve ♦ Motor innervation (Special Visceral Efferent) to the cricothyroid muscle (ONLY laryngeal m. not done by recurrent) Recurrent Laryngeal Nerves  Sensory (General Somatic Afferent) and parasympathetic (General Visceral Efferent) to laryngeal mucous membrane from vocal folds down  Motor innervation (Special Visceral Efferent) to muscles of larynx and cricopharyngeus muscle, Except Cricothyroid Cardiac Branches  Provides sensory (General Visceral Afferent) and preganglionic parasympathetic fibers to heart  

Passes through superior thoracic aperture into thorax Provides sensory (General Visceral Afferent) and preganglionic parasympathetic (General Visceral Efferent) innervation to organs of thorax

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Passes through esophageal hiatus as anterior and posterior vagal trunks Provides sensory (General Visceral Afferent) and preganglionic parasympathetic (General Visceral Efferent) innervation or organs of abdomen as far as left colic flexure

 CN11 (Accessory Nerve)  Enter/exit jugular foramen  Motor nerve with many branches, see Moore pgs. 666-667  CN12 (Hypoglossal Nerve)  Enter/exit hypoglossal canal  Motor nerve with many branches, see Moore pgs. 667-669 HEART  A review of the principle body cavities:  Posterior (dorsal) cavity  Cranial cavity – contains brain  Spinal cavity – contains spinal cord  The two cavities communicate through foramen magnum  The cavities are lined by meninges  Anterior (ventral) cavity  Thoracic cavity: • Pericardial cavity – surrounds heart • Pleural cavity (R & L) – each surrounds a lung ♦ The portion between the two pleural cavities is called the mediastinum (the heart & pericardial cavity are located here)  Abdominal cavity: • Abdominal cavity – contains the stomach, spleen, liver, gallbladder, pancreas, and small/large intestines • Pelvic cavity – contains the rectum and urinary bladder ♦ In the male, also the paried ductus deferens & seminal vesicle and prostate gland ♦ In the female, also the paired ovaries & the uterus  

Superior mediastinum: • Aortic arch w/ its branches, R & L brachiocephalic veins, upper ½ of SVC, trachea, esophagus, thoracic duct, thymus, phrenic nerve, vagus nerve, cardiac nerve, & left recurrent laryngeal nerve Inferior mediastinum: (T4 to T12) • 1) Anterior mediastinum – ♦ Part of the thymus gland ♦ Some lymph nodes ♦ Branches of the internal thoracic artery • 2) Middle mediastinum– ♦ Pericardium & Heart ♦ Phrenic nerves & its accompanying vessels • 3) Posterior mediastinum– ♦ Think of the 5 birds in the back of the thoracic cage:  Va-goose, Esopha-goose, Azy-goose, Hemiazy-goose& Thoracic duck ♦ Descending (thoracic) aorta ♦ Thoracic duct ♦ Esophagus ♦ Azygos system of veins (including hemiazygos vein) ♦ Vagus nerves – on the esophagus ♦ Splanchnic nerves ♦ Many lymph nodes ♦ Sympathetic chain ganglia (sympathetic trunks)  NOT phrenic nerves - that’s middle mediastinum • Cross Section at T8 of the Posterior Mediastinum ♦ From Back to Front  Vertebra  Splanchnic  Azygos vein  Thoracic duct (off-center to right)  Descending aorta (off-center to left)

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 Esophagus  Vagus Nerve around esophagus  Trachea (but here its already bisected into bronchi) HEART – general info:  Size of a closed fist  Located in the middle mediastinum  Two thirds of hearts mass is to the left of body midline  The developing Heart is anterior to the notochord (It delineates the posterior part of the heart……..  Surrounded by the Pericardium  Inner is the Visceral Pericardium (epicardium)  Outer is the Parietal Pericardium • Visceral and parietal pericardia are continuous at the veins & arteries entering & leaving the heart  Serous fluid fills in between to minimized friction went the heart beats  Close relation laterally to the phrenic nerves (which innervate the parietal pericardium)  The apex fits into a depression in the diaphragm Chambers of the Heart  2 Atria  Separated by thin, muscular interatrial septum  Fossa Ovalis • Shallow depression • Site of foramen ovale in the fetus, which permitted blood flow from atrium to atrium, bypassing pulm circ. ♦ The foramen eventually becomes closed with fibrous CT and becomes fossa ♦ Valve of foramen ovale lies in the medial wall of the left atrium • Anulis ovalis forms the upper margin of the fossa  2 Ventricles  Separated by thick, muscular interventricular septum  Apex of the heart located at level of the 5th intercostal space (left); Apex is formed by Left ventricle only.  Enlarge due to coarctation (constriction) from the aorta  Left ventricle is thicker Layers of the heart:  Internal endocardium:  Homologous with the tunica intima of the blood vessles  Lines the surface with simple squamous endothelium and underlying loose CT with small blood vessels  Myocardium:  Homologous to the tunica media  Bulk of heart mass with cardiac muscle cells arranged in the spiral configuration  Allows heart to wring blood from the ventricles toward aortic and semilunar valves  Right and left coronary arteries supply myocardium, come from ascending aorta  Epicardium or pericardium:  Serous membrane  Externally, it is covered by simple squamous epithelium supported by thin layer of CT  The adipose tissue that surrounds the heart accumulates in this layer Cardiac muscle:  Makes up myocardium  Intercalated discs to form a functional network  DOES NOT contract voluntarily  Fibers are separate cellular units, which don’t contain many nuclei  Respond to increase demands by increasing fiber size (compensatory hypertrophy)  Pectinate muscles:  Located on the inner surface of the right atrium  They are prominent ridges of atrial myocardium in right atrium and both auricles (which are small conical pouches projecting from the upper anterior portion of each atrium)  Crista terminalis:  Vertical muscular ridge that runs along the right atrial wall from the opening of the SVC to the IVC.  Provides origin of the pectinate muscle.  Represents junction btw the sinus venosus and the heart in the developing embryo  The line of junction between the primitive sinus venosus and the auricle  Also represented on the external surface of heart by the vertical groove called the sulcus terminalis  SA node is located in the crista terminalis near opening of SVC  Papillary muscles:  Cone-shaped muscles that terminate in tendinous cords (chordae tendineae that attach to the cusps of the AV valves)  Papillary muscles do not help the valves to close  Help prevent the cusps from being everted or blown out into the atrium during ventricular contraction

• Chordae tendinae do the same thing Sinus Venarum  Smooth portion of the right atrium  Develops from embryonic sinus venosus  Receives blood from sup. and inf. vena cavae, coronary sinus, and anterior cardiac veins  Separated from muscular portion by the Crista terminalis  Septomarginal Trabecula  Band of trabeculae carneae connect the interventricular septum to the base of the anterior papillary muscle  Contraction of this muscle prevents over distention of the ventricle  Interventricular Septum  Largely muscular, except for superior aspect, which is a small membranous portion that is common site for ventricular septal defects  Ligamentum Arteriosum  Remanants of Ductus Arteriosum (fetal bypass of pulm. circ)  Connects Aortic arch to Pulmonary Veins  Left Recurrent Laryngeal hooks around it  Valves: (TPMA – Tee Pee My Ace)  Tricuspid  best heard over the right half of the lower end of the body of the sternum  Anterior, Septal, Posterior cusps  Pulmonary  valve best heard over the second left intercostal space, just lateral to sternum  NO chordae tendinae or papillary muscles  Anterior, Right, and Left Semilunar cusps  More Anterior than Aortic Valve – (Remember that because it has an Anterior Cusp, where Aortic has Posterior)  Mitral valve (bicuspid)  best heard over apex of heart, (Left 5th intercostal space at the mid clavicular line)  Only valve of the 4 that has 2 cusps  Posterior and Anterior Cusps  Aortic valve  best heard over the second right intercostal space, just lateral to the sternum  NO chordae tendinae or papillary muscles  Left, Right, and Posterior Semilunar cusps. (Aortic has posterior, Pulmonary has Anterior – each has A & P)  Blood Flow  The cardiac veins lie superficial to the arteries  These all empty into the right atrium:  Coronary sinus • Largest venous pathway • Opens into the right atrium • Most of the cardiac veins empty here, except for anterior cardiac veins, which empty directly into the right atrium  Superior Vena Cava • Opens into the upper part of the right atrium • Returns blood from upper half of the body  Inferior Vena Cava • Larger than Superior VC • Opens into the lower part of the right atrium • Blood from lower half  Anterior Cardiac Veins – THINK ARTRIA Cardiac VEIN • Empty direct into R atrium  Then blood goes through the Tricuspid valve into the R ventricle then through Pulmonary valve and goes to pulmonary arteries/circulation  Blood gas exchange occurs and is return to heart via pulmonary veins  Increased resistance to pulmonary blood flow in the lungs would cause a strain on the right ventricle 

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Enters left atrium, passes through Mitral valve to left ventricle, and out the aortic valve to the rest of the body After entering the aorta, immediately the blood can leave the aorta through the right and left coronary arteries, sending blood right back to the heart • This does NOT happen during contraction of left ventricle • Coronary arteries fill during diastole  Obstruction of either artery can lead to anoxia to the heart, resulting in MI, spasms, or death The small and middle cardiac veins return blood from the myocardial capillaries to the Coronary Sinus –  Small comes from right  Middle from back The anterior interventricular artery accompanies the great cardiac vein The posterior interventricular artery accompanies the middle cardiac vein  **Thrombosis in coronary sinus might cause dilation in small, great, oblique, and middle cardiac veins, but NOT THE ANTERIOR cardiac vein  Anterior cardiac vein drains directly into the right atrium whereas all others drain into the coronary sinus.

 Impulse-conducting system of heart:  Consists of specialized cardiac muscle (which contain modified cardiac muscle fibers – THESE ARE NOT NERVES) present in the SA node, the AV node, and the Bundle of His (including the Purkinje fibers)  Fibers capable of depolarizing more rapidly than regular fibers, but are weakly contracting  The Sinoatrial node (SA node):  Located in the crista terminalis at the junction of the superior vena cava and the right auricle is the most rapidly depolarizing (Pacemaker)  Depolarizes spontaneously at 70 to 80 per minute  The conduction system of heart is all modified cardiac muscle fibers and NOT NERVES  Innervation to the heart is by the Vagus nerve and sympathetic nerves  SA Node  Atria  AV Node  AV Bundle  Purkinje fibers  Parasympathetic fibers from the vagus slow the heart where the sympathetic fibers from the sympathetic trunk speed up the heart beat  Usually (60% of the time) receives blood supply from the right coronary artery (AV node supplied by RCA, too)  Pericardial sac  With heart removed, look for the Transverse pericardial sinus (under the pulmonary trunk)  Also oblique pericardial sinus, is a cul-de-sac behind the heart RESPIRATORY SYSTEM  The Respiratory System:  Has two major parts—a branching, tree-like set of hollow tubes (the conducting airways) and very thin-walled pouches (the alveoli) at the ends of these tubes  Cartilaginous rings found in the main bronchi  Left lung has a smaller capacity than the right  Alveoli form the functional unit of the lung  Assists in vocalization and olfaction  Consists of the nasal cavity , pharynx, larynx, trachea, and the bronchi, bronchioles, and alveoli within the lungs  Lungs  Developed from an outpocketing of the gut tube (so did liver, pancreas, & gallbladder – not spleen)  Pair of resp organs that lie within the thoracic cavity and are separated by the mediastinum  Each lung is shaped like a cone  It has a blunt apex, a concave base (that sits on the diaphragm), a convex costal surface, and a concave mediastinal surface  At the middle of the mediastinal surface, the hilum is located  Which is a depression in which the bronchi, vessels, and nerves that form the root enter and leave the lung.  The small bronchial arteries also enter the hilum of each lung and deliver oxygen rich blood to the tissues  They tend to follow the bronchial tree to the respiratory bronchioles where they anastomose with the pulmonary vessels  Branches of the vagus nerve also pass the hilum of each lung  Innervation is by what? - the Vagus nerve and sympathetic chain ganglia nerves  Right lung:  Has 3 lobes (superior, middle, and inferior) and three secondary (lobar) bronchi  Contains ten bronchial segments (tertiary bronchi)  Usually receives one bronchial artery  Slightly larger capacity than the left lung  More common to aspirate foreign bodies into the Right lung (less acute angle)  Left Lung:  Has 2 lobes (superior and inferior) and two secondary (lobar) bronchi separated by an oblique fissure • Two lobes because the heart takes up too much space for a third lobe  Contains eight bronchial segments (tertiary bronchi)

 Contains a cardiac notch on its superior lobe  VERY ODD  Usually receives two bronchial arteries (Where Right only gets 1, eventhough 3 lobes)  Contains a lingula—a tongue-shaped portion of its superior lobe that corresponds to the middle lobe of the right lung.  A stab wound creating a pneumothorax on the left side would result in the collapse of the left lung only  Hilum  Pulmonary Veins usually anterior and inferior  Pulmonary Arteries are then Anterosuperior  Brochus usually most posterior  Structure of the Lung:  Each lung is enclosed in a double-layers sac called the pleura  One layer is called the visceral pleura, the other is called the parietal pleura  Between the two layers is the pleural cavity, which is filled with serous fluid  Root of the lung – major structures found therein:  1) Primary bronchus—arise from trachea and carry air to the hilum • Part of the conducting division of the respiratory system = pulmonary conduction system  2) Pulmonary artery—enters the hilum of each lung carrying oxygen poor blood  3) Pulmonary veins—superior and inferior pair for each lung leave the hilum carrying oxygen rich blood  Top to Bottom:  Trachea:  Tube that begins below the cricoid cartilage (C6) of larynx and splits at the level of the sternal angle (T5) [about the same level where the trachea passes behind the aortic arch] where it divides at the carina into primary bronchi (right and left primary or mainstem bronchus, which lead to each lung and are part of the pulmonary conduction system • Two main bronchi branches divide into five lobar bronchi (secondary bronchi): ♦ Right main bronchus divides into three lobar bronchi  Straighter, shorter, and larger than the left primary bronchus  It is also in a more direct line with the trachea (important in dental chair because if patient swallows an object it tends to lodge in the right bronchus) ♦ Left main bronchus divides into two lobar bronchi • Each secondary or lobar bronchus serves one of the five lobes of the two lungs ♦ Secondary bronchi branch into tertiary bronchi (segmental bronchi) which continue to divide deeper in the lungs into tiny bronchioles, which subdivide many times, forming terminal bronchioles  Each of these terminal bronchioles gives rise to several respiratory bronchioles  Each respiratory bronchiole subdivides into several alveolar ducts, which end in clusters of small, thinwalled air sacs called alveoli • These alveoli open into a common chamber called alveolar sac, which forms the lung’s functional unit  Bronchus  Differs from a bronchiole by possessing cartilage plates & pseudostratified columnar epi  Main support provided by Hyaline Cartilage  Bronchioles  Characterized by: • Diameter < 1mm • Epithelium that progresses from ciliated pseudostratified columnar to simple cuboidal (respiratory bronchioles) • Small bronchioles have non-ciliated bronchiolar epithelial cells (Clara cells) that secrete GAGs that protect the lining • No glands, no hyalinecartilage, no lymphatic nodules ♦ Smaller diameter prevents them from collapsing at end of expiration • Scattered goblet cells • Abundant smooth muscle to regulate the bronchiolar diameter ♦ Variation of the size of the lumen of the bronchiole during inspiration and expiration is caused primarily by smooth muscle and elastic fibers • Contraction is from parasymp stimulation  *Conduction bronchioles  Smaller extensions of bronchi (little bronchi)  Those devoid of alveoli in their walls are nearer the hilum of the lung  *Terminal bronchioles  Lined by low columnar epithelium  *Respiratory bronchioles  Continues to progress to low simple cuboidal  Continuing from terminal bronchioles, branch nearer the alveolar ducts and sacs and have occasionally alveoli in their walls  These bronchioles capable of respiring are the first generation of passageways of the respiratory portion of the bronchial tree  As air passes from the trachea into the lungs, the respiratory bronchiole is the 1st structure in which gaseous exchange through the wall of an alveolus may occur

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In proceeding from the bronchus to the respiratory bronchiole, there is a decrease in cartilage and an increase in elastic fibers  In proceeding from the trachea to a respiratory bronchiole, the following structural changes occur: • Decrease in goblet cells, decrease in ciliated cells, total loss of cartilage from the walls ♦ Not a progressive change from stratified squamous to cuboidal epithelial lining (from Columnar to cuboidal)  As you go down respiratory tract what is the last thing to go ♦ Smooth muscle??? – See physio book  Cells  Type I Pneumocyte • Account for 97% of alveolar lining • Extremely thin (as thin as 25 nm) • Provide minimal barrier to facilitate diffusion of gas  Type II Pneumocyte (GREAT cells) • Account for 3% of alveolar surface • Produce/secrete surfactant (a lecithin) ♦ Phosphlipid-containing substance that reduces surface tension  Pharynx (throat) tube  Serves as passageway for respiratory and digestive tracts. Extends from mouth and nasal cavities to the larynx and esophagus. Has three regions:  Nasopharynx: • Contains the eustachian canal (connects the nasopharynx to middle ear), salpingopharygeal fold, pharyngeal recess, & pharyngeal tonsils (called adenoids when inflamed), (not piriform recess) – Which is on either side of eipiglottis • Lies above the soft palate and is continuous with the nasal passage • Lies directly behind the nasal cavities or choanae ♦ The pharyngeal tonsils may become inflamed & block the choanae, causing pt to become a mouth breather • The tensor veli palatine and the levator veli palatine muscles prevent food from entering the nasopharynx ♦ The uvular muscle does, too, but it wasn’t an answer option  Oropharynx: • Extends from the plane passing through the anterior pillars to the beginnings of the laryngopharynx • It communicates with the oral cavity through the isthmus of the fauces • Oral part of the Pharynx communicates directly with the Nasopharynx and the Laryngopharynx • Receives food from mouth and air from nasopharynx • Contains palatine and lingual tonsils • Between the soft palate and the epiglottis  Laryngopharynx (also hypopharynx): • Extends from the oropharynx (tip of the epiglottis and inferior) • The SUBGLOTTIS receives sensory innervation from the Superior Laryngeal Nerve • Serves as a passageway for food and air • Air entering the laryngopharynx goes to the larynx while food goes to the esophagus ♦ Food entering the larynx would be expelled by violent coughing  Swallowing  Food moves from oropharynx , prompting soft palate to rise and seal off the nasopharynx.  Epiglottis bends downward while the laryngeal apparatus moves upward, closing off the laryngeal inlet (Aditus)  Bolus of food cascades around the epiglottis and passes through the piriform fossae (recesses) on either side to enter the esophagus  We swallow 2000 times a day  Mostly done during the daytime, NOT eating  Nose:  What makes up the nose?  Medial and lateral nasal processes  Air enters through nostrils (external nares) lead to the vestibules of the nose  The bony roof of the nasal cavity is formed by the cribiform plate of the ethmoid bone  The lateral walls have bony projections called conchae that form shelves which have spaces beneath them called meatuses  The paranasal sinuses  (maxillary, frontal, ethmoidal, and sphenoidal) drain into the nasal cavity by way of these meatuses  The nasal bone does NOT contain paranasal sinuses  Maxillary is the Largest Paranasal sinus  NOTE: Sphenoidal sinus doesn’t drain into any of the meatuses  The nasolacrimal duct—drains tears from surface of eyes, also empties into the nasal cavity by way of the inferior meatus  The floor is formed by the hard palate  Nasal cavity & oral cavity are connected by the incisive foramen??? (other options: gr. pal. & less. pal)  The nasal cavity opens posteriorly into the nasopharynx via a funnel-like opening called the choanae (posterior nares)

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Epithelium:  Vestibules are lined with nonkeratinized stratified squamous epithelium  Conchae of the nasal fossae and the sinuses are lined with pseudostratified ciliated columnar epithelium • The cell of the maxillary sinus is pseudostratified ciliated columnar epithelium  The specialized columnar epithelium is very prominent in the upper medial portion of the nasal cavity  The nasal cavity receives sensory innervation from the olfactory nerve for smell and from the trigeminal nerve for other sensations  Nasal cavities lined with specialized columnar epithelium (called olfactory epithelium)  Blood supply is from the branches of the ophthalmic and maxillary arteries  Emergency tracheotomy:  Tracheotomy allows for air to pass between the lungs and the outside air  Done in the cricothyroid space (between thyroid and cricoid cartilage) or through the median cricothyroid ligament  Most easily made by an incision through the median cricoid cartilage to the thyroid cartilage and is inferior to the space between the vocal cords (rima glottides) where aspirated objects usually get lodged  If you cut below the cricoid cartilage you will damage the trachea  What type of epithelium is covering the vocal folds???  Upper vocal folds (FALSE folds)  Psuedostratified  Lower vocal folds (TRUE folds)  Nonkeratinized stratified squamous REPRODUCTIVE SYSTEM Organs of the Female Reproductive System  Ovaries  Are almond-shaped organs located on either side of the uterus, but vary with age.  Round, smooth, and pink at birth  Grow larger, flatten and turn grayish by puberty  During childbearing years take on almond shape and rough, pitted surface  After menopause, they shrink and turn white  Produce ova and steroid hormones:  Estrogen—stimulates the development of the female sex organs, the breast, and various secondary sexual characteristics  Progesterone—stimulates secretion of uterine milk by the uterine endometrial glands; also promote development of the secretory apparatus of the breasts  Purpose of ovaries is to produce mature ova  Oogonia—serve as source of oocytes  1° oocytes begin meiosis I during fetal life & complete meiosis I just prior to ovulation  During the in between year, meiosis I is arrested in prophase  Meiosis II is arrested in METaphase until fertilization (until the egg has MET a sperm)  Just prior to ovulation the preovulatory follicle produces and secretes large amounts of Estrogen  Primordal follicles—containing oocytes in their sexually mature ovary are stimulated to develop by secretion of FSH from the anterior lobe of the pituitary  Primary follicles (in first meiotic division) become secondary follicles with the formation of the antrum (cavity)  Fully mature Graafian follicles containing secondary oocytes (in second meiotic division) release the egg into the abdominal cavity under the influence of LH to be swept into the ostium of the Fallopian tube (uterine tube, oviduct) to be fertilized and subsequently implanted in the uterus or discarded if not fertilized  During maturation of the egg, four daughter cells are produced, one of which is the large fertilizable ovum, while the others are small, rudimentary ova known as polar bodies or polocytes.  Zona pellucida is associated with a oocyte in a mature follicle  Atretric Follicles  A follicle that degenerates before coming to maturity; great numbers of such atretic follicles occur in the ovary before puberty; in the sexually mature woman, several are formed each month  Corpus luteum  Endocrine body that secretes progesterone and is formed in the ovary at the site of a ruptured ovarian (Graafian) follicle immediately after ovulation.  If pregnancy does not occur, the corpus luteum regresses to a mass of scar tissue (corpus albicans) which eventually disappears.  If pregnancy does occur—corpus luteum persists for several months until the placenta matures enough to produce the hormones  Develops directly from the cells remaining in the remnants of the preovulatory follicle after ovulation  In the ovary:  Progesterone production is primarily by the corpora lutea  Uterine/Fallopian Tubes  Convey secondary oocyte toward the uterus  Site of fertilization (Especially the Ampulla)  Convey developing embryo to uterus  Uterus  The uterine cavity is roughly triangular in shape and compressed in an anteroposteriorly

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Site of implantation  Blastocyst usually occurs in the upper portion of the uterine cavity  Protects and sustains life of embryo and fetus during pregnancy  Active role in parturition  Source of menses  Round ligament of the uterus normally found in the inguinal canal of the female.  It is a fibromusuclar band attached to the uterus on either side in front of and below the openings of the fallopian tube. It passes through the inguinal canal to the labia majora  Vagina  Conveys uterine secretions to outside of the body  Receives erect penis and semen during coitus and ejaculation  Passage for fetus during parturition  Path of menstrual flow to outside  Mammary Glands  Produces and secretes milk for nourishment of an infant  Lie in the superficial fascia – not the deep fascia.  Are actually a modified sweat gland  Contain myoepithelial cells (aka basket cells) (star-shaped)—have processes that spiral around some of the secretory cells of these glands  Contraction forces the secretion of the glands toward the ducts  Located in the spaces between the basement membrane and secretory cell!!!!!  The breast receives arterial blood through branches of the lateral thoracic (branch of the axillary artery) and internal thoracic arteries  Coopers’ ligaments support breasts—are strong, fibrous processes that run from the dermis of the skin to the deep layer of superficial fascia through the breast  Nipple usually lies at the level of the fourth intercostal space  Breast cancer causes dimpling of the overlying skin and nipple retraction  Most of the lymph from the mammary glands goes to the axillary lymph nodes Organs of the Male Reproductive System  Testis  Testis produce spermatozoa and secret sex hormones  They are firm, mobile organ lying within the scrotum  Each develops retroperitoneally and descends into the scrotum about time of birth  Seminiferous tubules  Sperm are produced in the seminiferous tubules and stored outside the testis in the epididymis until ejaculated  Meiosis occurs here (it does NOT occur in the ductus epididymis, stratum germanitivum, or ovarian germinal epi)  Lining consists of a complex stratified epithelium  Contain two cell types:  Sertoli cells • Produce spermatozoa • Form the blood-testes barrier with tight junctions connecting each cell  Spermatogenic cells – germ cells found between Sertoli cells • The development of germ cells depends on pituitary FSH & testicular testosterone  Interstitial cells  Produce and secrete male sex hormones  Androgens, the most important one being testosterone, are synthesized and secreted into the blood stream by interstitial cells (of Leydig) found in the interstitium of the testis between the seminiferous tubules  Testosterone is required for development of the testes and secondary sex characteristics and initiation and maintenance of sperm production and secondary sex characteristics.  Epididymis  One found on each testis  Epididymis displays stereocilia  It is a tortuous, C-shaped, cordlike tube located in the scrotum  Tube emerges from the tail as the vas deferens, which enters the spermatic cord  Provides storage space for the spermatozoa and allows them to mature  Carries sperm from the seminiferous tubules of the testis to the vas deferens  Ductus Deferens (Vas)  Store spermatozoa  Conveys sperm from the epididymis to the ejaculatory duct  Cordlike structure  Contains Stereocilia also  Ejaculatory Duct  Receive spermatozoa and additives to produce seminal fluid

 Passageway formed by the union of the deferent duct (vas deferens) and the excretory duct of the seminal vesicle  The ejaculatory duct opens into the prostatic urethra  Speaking of ejaculation: just think, “Point & Shoot” = Parasympathetic for erection, Sympathetic for emission  Seminal Vesicles  Secrete alkaline fluid containing nutrients and prostaglandins  Prostate Gland  Secretes alkaline fluid that helps neutralize acidic seminal fluid and enhance motility of spermatozoa  Scrotum  Encloses and protects testes  Penis  Conveys urine and seminal fluid to outside of the body  Sperm development:  Spermatogenesis occurs in Seminiferous tubules  Spermatogonium→1° spermatocyte→2° spermatocyte→Spermatid  Diploid, 2N→Diploid, 4N→Haploid, 2N→Haploid, N  Organs that produce semen:  Seminal vesicles—paired sacs at the base of the bladder  Bulbourethral gland (Cowper’s gland)—paired located inferior to the prostate  Prostate gland—under the bladder and surrounds the urethra. Continually secretes prostatic fluid, a thin, milky, alkaline fluid.  Copora amylacea are present in the alveoli of this gland  Inguinal canal:  It transmits the spermatic cord in males and the round ligament of the uterus in females; as well as the ilioinguinal nerve in both sexes  It begins at the deep inguinal ring and extends to the superficial inguinal ring  It is much larger in males than in females:  The anterior wall is formed by aponeuroses of the external oblique and partially by the internal oblique muscle  Passes: • Cremaster muscle • Testicular artery • Internal spermatic fascia • Pampiniform plexus of vein • NOT the epidiymis (…that would be down in the scrotum)  Spermatic Cord  Covered by 3 concentric layers of fascia derived from the layers of the anterior abdominal wall  Internal and external spermatic fascia  Cremasteric fascia (cremaster muscle and fascia)  Spermatic cord contents:  Testicular artery: branch of the abdominal aorta; supplies mainly the testis and cremaster muscle  Testicular veins: pampiniform plexus forms testicular veins; drains into the left renal vein on the left side and into the inferior vena cava on the right side  Urethra  Passageway for urine between the urinary bladder and the outside of the body  Female urethra  4 cm  Females have more frequent bladder infections  Opens into the vestibule between the clitoris and the vagina  Male urethra  20 cm because it travels in the penis  Ureter  Paired passageway which transports the urine from the kidney to the urinary bladder for concentration and storage until voided Reproductive Anatomy  See Kaplan pp. 515-521 for all the details  Hyoglossus and Mylohyoid Relationships  Lingual Nerve, Hypoglossal nerve, Submandibular Duct ♦ SubMan duct and lingual nerve cross 2 x  ALL superficial (Lateral) to the Hyoglossus  ALL deep (medial) to the Mylohyoid  Lingual Artery  Deep to BOTH (Medial)  Which nerve does NOT follow its artery???

 Lingual nerve  External Carotid  What nerve follows the external carotid??  Great Auricular Nerve???