Anatomy & physiology Mid-semster study notes.pdf

Anatomy & Physiology Study Notes ANATOMY OVERVIEW ANATOMY – study of the structure of the body parts & relationship to one another

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Gross/macroscopic Microscopic Developmental (structural changes throughout life)

PHYSIOLOGY – study of function of the body’s structural machinery - Considers operation of specific organ systems i.e. Renal – kidney function - Focuses on functions of body at cellular/molecular level GROSS ANATOMY - REGIONAL – all structures in one part of body i.e. abdomen or leg - SYSTEMIC – studied by system - SURFACE – study of internal structures as they relate to the overlying skin MICROSCOPIC - CYTOLOGY – study of the cell - HISTOLOGY – study of tissues STRUCTURE GOVERNS FUNCTION – WHAT A STRUCTURE CAN DO DEPENDES ON SPECIFIC FORM - Chemical – atoms combined to from molecules - Cellular – cells made of molecules - Tissue – consists of similar types of cells - Organ – made up of different types of tissues - Organ system – consists of different organs that work together - Organismal – made up of the organ systems

ORGAN SYSTEMS OF THE BODY

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INTEGUMENTARY SYSTEM (Hair, Skin, Nails) External body covering, protects deeper tissue from injury, synthesises vit D Site of cutaneous (pain receptors), sweat & oil glands

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SKELETAL SYSTEM (Bones, Joints) Protects/supports body organs Framework for muscle use to cause movement Blood cells formed in bones, stores minerals

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MUSCULAR SYSTEM (Skeletal muscles) Manipulation of the environment, locomotion, facial expressions Maintains posture & heat

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NERVOUSE SYSTEM (Brain, sensory receptor, Nerves, Spinal cord) Fast acting control system of the body Responds to external/internal changes by activating appropriate muscles, glands ENDOCRINE SYSTEM (Thyroid gland, Pineal gland, Pituitary gland, Thymus, Adrenal gland, Pancreas, Ovary, Testis) Glands secrete hormones – regulate processes such as growth, reproduction, nutrient use(metabolism) by body cells

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CARDIOVASCULAR SYSTEM (Heart, Blood vessels) Blood vessels transport blood – carries oxygen, carbon dioxide, nutrients, wastes etc. The heart pumps blood

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LYMPHATIC SYSTEM/IMMUNITY (Red bone marrow, Thymus, Lymphatic vessels, Thoracis duct, Spleen, Lymph nodes) Picks up fluid leaked from blood vessels & returns it to blood Disposes of debris in lymphatic stream Houses white blood cells(Lymphocytes) involved in immunity Immune response mounts attack against foreign substances within body

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RESPIRATORY SYSTEM (Nasal cavity, Pharynx, Larynx, Trachea, Lung, Bronchus) Keeps blood constantly supplied with oxygen, removes carbon dioxide Gaseous exchanges occur through walls of the air sacs in lungs

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DIGESTIVE SYSTEM (Oral cavity, Esophagus, Liver, Stomach, Small intestine, Large intestine, Rectum, Anus) Breaks down food into absorbable units that enter blood for distribution to body cells Indigestible foodstuffs are eliminated as faeces

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UNINARY SYSTEM (Kidney, Urinary bladder, Urethra, Ureter) Eliminates nitrogenous wastes from the body Regulates water, electrolyte & acid base balance of the blood

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MALE REPRODUCTIVE SYSTEM (Prostate glands, Ductus deferens, Scrotum, Penis, Testis) Production of offspring Testis produce sperm & male sex hormone Ducts & glands aid in delivery of sperm to female reproductive tract

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FEMALE REPRODUCTIVE SYSTEM (Mammary glands, Ovary, Uterine tube, Uterus, Vagina) Ovaries produce eggs & female sex hormone Remaining structures serve as sites for fertilization & development of fetus Mammary glands produce milk to nourish newborn

SURVIVAL NEEDS -

Nutrients – chemical substances used for energy/cell building Oxygen – needed for metabolic reactions Water – provides necessary environment for chemical reactions Maintain normal body temperature – necessary for chemical reactions to occur at life sustain rates Atmospheric pressure – required for proper breathing, gas exchange in lungs

HOMEOSTASIS

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The ability to maintain relatively stable internal environment in an ever changing outside world Internal environment – in a dynamic state of equilibrium Chemical, thermal, neural factors interact to maintain homeostasis

HOMEOSTATIC CONTROL MECHANISMS -

Variable produces change in body Three interdependent components of control mechanisms 1. Receptor – monitors environments – responds to changes (stimuli) 2. Control centre – determines set point at which variable is maintained 3. Effector – provides means to respond to stimulus

NEGATIVE FEEDBACK - In negative feedback systems – output shuts off original stimulus e.g. regulation of blood glucose levels POSTIVE FEEDBACK - In positive feedback systems, output enhances/exaggerates original stimulus e.g. regulation of blood clotting

BODY CAVITIES -

DORSAL – protects nervous system & has 2 subdivisions 1. Cranial cavity – within skull encases brain 2. Vertebral cavity – runs within vertebral column ,encases spinal cord

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VENTRAL CAVITY – houses internal organs (viscera) & divided into 2 subdivisions 1. THORACIC CAVITY – subdivided into Pleural cavities (each houses a lung) - MEDIASTINUM – pericardial cavity surrounds remaining thoracic organs - PERICARDIAL CAVITY – encloses the heart 2. ABDOMINOPLEVIC CAVITY – separated from superior thoracic cavity by dome shaped diaphragm, has 2 subdivisions - ABDOMINAL CAVITY – contains stomach, intestines, spleen, liver, & other organs - PELVIC CAVITY – lies within pelvis, contains bladder, reproductive organs, rectum, Ventral body Cavity Membranes

ABDOMINOPELVIC RETIONS

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Umbilical Epigastria Hypogastric Right & Left Iliac or Inguinal Right/Left Lumbar Right/Left Hypochondriac

UMBILICAL

LUMBAR

HYPOGASTRIC

HYPOCHONDRIAC

INGUINAL

EPIGASTRIC

ORGANS OF THE ABDOMINOPELVIC REGIONS

DORSAL VERTABRAL

VENTRAL PELVIC

VENTRAL PERICARDIAL

DORSAL CRANIAL

VENTRAL ABDOMINAL

VENTRAL PLEURAL

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The heart lies in the VENTRAL PERICARDIAL What is not part of the dorsal cavity? THORACIC CAVITY Organised groups of cells (plus their intercellular substances) that have a common purpose form a(n) TISSUE Feedback mechanisms – NEGATIVE FEEDBACK MECHINISIMS TEND TO DECREASE THE ORIGINAL STIMULUS Homeostatic imbalance - IS CONSIDERED THE CAUSE OF MOST DISEASES Histology is the study of – TISSUES The correct sequence from simplest to most complex – ATOMS, MOLECULES, CELLS, TISSUES, ORGANS One of the functional characteristics of life is irritability – SENSING CHANGES IN THE ENVIRONMNET & THEN REACTING OR RESPONDING TO THEM A parasagittal plane is – ANY SAGITAL PLANE EXCEPT THE MEDIAN A horizontal section through the body is called – TRANSVERSE A vertical section through the body, dividing it into anterior & posterior, is called FRONTOL/CORONAL

MUSCULOSKELETAL ANATOMY – VERTEBRAL COLUMN VERTEBRAL COLUMN - Formed from 26 irregular shaped bones (vertebrae) - CERVICAL VERTEBRAE – 7 bones of the neck - THORACIC VERTEBRAE – 12 bones of the torso - LUMBAR VERTEBRAE – 5 bones of the lower back - SACRUM – bone inferior to lumber vertebrae, articulates with hip bones (fused triangle shape, no movement)

VERTABRAL COLUMN LIGAMENTS

GENERAL STRUCTURE OF VERTEBRAE -

Spinious processes (SP) project posteriorly & transverse processes project laterally Superior & inferior articular processes – protrude superiorly & inferiorly from pedicle-lamina junctions Intervertebral foramina – lateral openings formed from notched areas on superior & inferior borders of adjacent pedicles

CERVICAL VERTEBRAE -

Seven vertebrae (C1-C7) are the smallest, lightest vertebrae C3-C7 are distinguished with an oval body, short Spinious processes, & large, triangular vertebral foramina Each transverse process contains a transverse foramen

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CERVICAL VERTEBRAE – THE ATLAS (C1) – has no body or Spinious process Has anterior/posterior arches & 2 lateral masses CERVICAL VERTEBRAE – THE AXIS (C2) Axis has a body, spine, vertebral arches Unique to the axis – the Dens (odontoid)process, projects superiorly from body & cradled in anterior arch of atlas Dens is pivot for rotation of the atlas THORACIC VERTEBRAE Twelve vertebrae (T1-T12) which articulate with ribs Major markings; two facets & two demifacets on heart-shaped body, the circular vertebral foramen, transverse processes, & a long spinous process Location of articulate facets prevents flexion/ extension, allows rotation of this area of the spine LUMBAR VERTEBRAE five lumbar vertebrae (L1-L5) are located small of back & have an enhanced weight-bearing function They have short, thick pedicles and laminae, flat hatchet-shaped spinous processes, & triangularshaped vertebral foramen Orientation of articular facets locks lumbar vertebrae together to provide stability

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SACRUM five fused vertebrae (S1-S5), shape posterior wall of pelvis It articulates with L5 superiorly, & with auricular surfaces of hip bones Major markings include sacral promontory, transverse lines, alae, dorsal sacral foramina, sacral canal, & sacral hiatus

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COCCYX (TAILBONE) The coccyx is made up of four (some cases Three- five) fused vertebrae that articulate superiorly with sacrum

ABDOMINAL MUSCLES -

Composed of 4 paired muscles (internal/external obliques, transverses abdominis, rectus abdominis), their fasciae & aponeuroses Fascicles of muscles run at right & oblique angles to one another, giving abdominal wall added strength Involved with flexion, lateral flexion & rotation of trunk Promote urination, defecation, childbirth, vomiting, coughing, screaming

THE THORAX – MUSCLES OF RESPERATION - Function of thoracis muscles, promote movement for breathing - External intercostals – superficial layer – lifts ribcage, increases thoracic volume to allow inspiration - Internal intercostals - deeper layer – aids in forced expiration - Diaphragm – most important muscle to inspiration

CHEMISTRY – MATTER & ENERGY STATES OF MATTER - Solid – definite shape/volume - Liquid – definite volume, changeable shape - Gas – changeable shape, volume ENERGY – the capacity to do work (matter into motion) - KENETIC – energy in action - POTENTIAL – energy of position; stored (inactive) energy - EXERGONIC – chemical reactions which release energy - CATOBOLIC – a release of energy FORMS OF ENERGY - Chemical – stored in the bonds of chemical substances - Electrical – results from movement of charged particles - Mechanical – directly involved in moving matter - Radiant/electromagnetic – energy traveling in waves (i.e. visible light, ultraviolet light, X-rays)       

ELEMENTS – UNIQUE SUBSTANCES , CANNOT BE BROKEN DOWN BY ORDINARY CHEMICAL MEANS ATOMS – MORE OR LESS IDENTICAL BUILDING BLOCKS FOR EACH ELEMENT ATOMIC SYMBOLS – ONE OR TWO LETTER CHEMICAL SHORTHAND FOR EACH ELEMENT ATOMIC NUMBER = EQUAL TO NUMBER OF PROTONS MASS NUMBER = EQUAL TO MASS OF PROTONS & NEUTRONS ATOMIC WEIGHT = AVERAGE OF THE MASS NUMBERS OF ALL ISOTOPES MOLECULE – 2 OR MORE ATOMS HELD TOGETHER BY CHEMOCAL BONDS

ATOMIC STRUCTURE   -

NECLEUS – consists of neutrons & protons NEUTRONS – No charge & mass of 1 atomic mass unit (amu) PROTONS – have a positive charge & mass of 1 amu ELECTRONS – found orbiting nucleus Have a negative charge & 1/2000 the mass of a proton (O amu)

MODELS OF THE ATOM  

PLANTARY MODEL – electrons move around nucleus in fixed circular orbits ORIBITAL MODEL – regions around nucleus in which electrons are most likely to be found

COLLOIDS & SUSPENSIONS -

SUSPENSIONS – heterogeneous mixtures with visible solutes, tend to settle out COLLOIDS (EMULSIONS) – heterogeneous mixtures whose solutes do not settle out – colloid properties important in connective tissue behaviour Difference between a COLLOID & a SUSPEENSION is – a colloid can undergo sol-gel transformation, suspension cannot

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COMPOUND – 2 OR MORE DIFFERENT KINDS OF ATOMS CHEMICALLY BONDED TOGETHER - Cannot be separated by physical means - All compounds are homogeneous

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MIXTURES – 2 OR MORE COMPONENTS PHYSICALLY INTERMIXED (NOT CHEMICALLY BONDED). - No chemical bonding takes place in mixtures - Most can be separated by chemical means - Can be heterogeneous/homogeneous

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SOLUTIONS – HOMOGENOUS MIXTURES OF COMPONENTS -Solvent – substance present in greatest amount - Solute – substance(s) present in smaller amounts

ANABOLISIM - Atoms or molecules combine to form larger/complex molecules - Involves building both larger molecules & breaking down others CHEMICAL BONDS -

ELECTRON SHELLS/ENERGY LEVELS – surround nucleus of an atom BONDS – formed using electrons in outermost energy level VALENCE SHELL – outermost energy level containing chemically active electrons OCTET RULE – except for 1st shell which is full with 2 electrons, atoms interact in a manner to have 8 electrons in their valence shell

CHEMICALLY INERT ELEMENTS -

Outermost energy level fully occupied by electrons

CHEMICALLY REACTIVE ELEMENTS -

Do not have outermost energy level fully occupied by electrons

TYPES OF CHEMICAL BONDS: IONIC BONDS - Charged atoms resulting from the gain or loss of electrons - Form between atoms by transfer of one or more electrons - Ionic compounds form crystals instead of individual molecules e.g. Sodium chloride (NaCI) COVALENT BONDS - Formed by the sharing of two or more electrons - Electron sharing produces molecules HYDROGEN BONDS - too weak to bind atoms together - Common in dipoles e.g. water - Responsible for surface tension in water - Important as intermolecular bonds, giving molecule three dimensional shape

POLAR AND NONPOLAR MOLECULES -

Non-Polar molecules = Electrons shared equally between atoms Polar molecules = Unequal sharing of electrons Electronegative = Atoms with six/ seven valence shell electrons Electropositive = Atoms with one or two valence shell electrons

FACTORES INFLUENCING RATE OF CHEMICAL REACTIONS - Temperature – reactions proceed quicker at higher temps (importance of homeostatic temp) - Particle size – smaller the particle, faster the chemical reaction - Concentration – higher reacting particle concentrations produce faster reactions - Catalysts – increase the rate of a reaction without being chemically charged - Enzymes – Biological catalysts            

If an atom has 6 protons and 6 electrons how many electrons are in the outer (valence) shell? 4 If an atom has an atomic number of 6 and a mass number of 12. How many neutrons does this atom have? 6 If an element has 7 electrons in its outer (valence) shell, what would the charge of its ion be?-1 If an element has 2 electrons in its outer (valence) shell, what would the charge of its ion be? +2 If an element has 6 electrons in its outer (valence) shell, what would the charge of its ion be? -2 An Atoms has a mass number of 25 and contains 13 neutrons how many electrons does this atom have? 12 The atomic number of an element INDICATES THE NUMBER OF PROTONS Atoms – ARE UNCHARGED PARTICLES In an ionic bond – ELEMENTS EITHER DONATE OR RECEIVE AN ELECTRON An atom has 9 protons to become stable what will happen? THE ATOM WILL GAIN ONE ELECTRON In a hydrogen bond – THE NEGATIVE POLE OF A MOLECULE BINDS WTH THE POSTIVE POLE OF ANOTHER MOLECULE In a single covalent bond - TWO ELEMENTS SHARE AN ELECTRON

ORGANIC CHEMISTRY CLASSES OF COMPOUNDS 

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INORGANIC COMPUNDS – water, salts, many acid bases - Does not contain carbon - CO₂ & CO ORGANIC COMPOUNDS – carbohydrates, fats, proteins, nucleic acids, lipids - Contain carbon, usually large – covalently bonded - Unique to living systems - Many are POLYMERS – chains of similar units - Synthesized by dehydration synthesis - Broken down by hydrolysis reactions

WATER - Most important INORGANIC compound in living organisms -

HIGH HEAT CAPACITY – absorbs/releases heat with little temp change Prevents sudden changes in temp HIGH HEAT OF VAPORIZATION – evaporation requires large amounts of heat - Useful cooling mechanism PROPERTIES OF WATER - POLAR solvent properties – dissolves/dissociates ionic substances - Forms hydration layers around large charged molecules e.g. proteins (colloid formation) - Body’s major transport medium ACIDS & BASES - Both are electrolytes ACIDS are proton (hydrogen ion) donors (release H in solution) - Acid solutions contain H – as H increases, acidity increases - ↑(H), ↓pH BASES are proton acceptors (take up H from solutions) - Alkaline solutions contain BASES (e.g. OH) - As (H) decreases (or as (OH) increases, alkaline increases - ↓(H), ↑pH NEUTRAL SOLUTIONS - Pure water is pH neutral (= numbers of H & OH) - All neutral solutions are pH 7 ACID BASED HOMEOSTASIS - ph change interferes with cell function, may damage living tissue - slight change in pH can be fatal - ph regulated by kidneys, lungs, buffers (mixture of compounds that resist pH changes) - BUFFERS convert strong (completely dissociated) acids or bases into weak (slightly dissociated) ones ORGANIC COMPOUNDS CARBOHYDRATES - Sugars & starches - Contain C, H, & O - Major source of cellular fuel (e.g. glucose) - Structural molecules (ribose sugar in RNA) - 3 classes  Monosaccharaides  Disaccharides  Polysaccharides

MONOSACCHARIDES - Simple sugars containing 3 to 7 C atoms DISACCHARIDES - Double sugars - Too large to pass through cell membranes Sometimes organisms link sugar molecules in pairs to form disaccharides e.g. - Sucrose - Plants make sucrose by joining glucose & fructose - sucrose circulates in plants & sap & we obtain it from sugar Cain e.g. table sugar - Lactose - formed by galactose & glucose, lactose is the disaccharide that gives milk its sweet taste - Maltose - formed by two linked glucose molecules, digestion of starch in a sprouting seed or in the intestinal of an animal produces this disaccharide POLYSACCHARIDES - Polymers (long chains) of simple sugars e.g. starch, glycogen consisting of thousands of linked monosaccharaides - Not very soluble LIPIDS (mostly PHOSPHOLIPIDS) - Contain C, H, O (less than carbohydrates), sometimes P - Insoluble in water - Main types – Neutral fats/triglycerides, phospholipids, steroids, Eicosanoids TRIGLYCERIDES - Neutral fats – solid fats & liquid oils - Composed of 3 fatty acids bonded to a glycerol molecule - Fat molecules do not mix with water, because they have 3 long hydro carbon tails - Main functions;  Energy storage (tails hold more potential energy than other biological molecules)  Insulation  Protection

PHOSPHOLIPIDS - Modified triglycerides – Glycerol + 2 fatty acids & a phosphorus (P) containing group - Head & tail regions have different properties - Important in cell membrane structure

STEROIDS - interlocking 4 ring structure - Cholesterol, vit D, steroid hormones & bile salts PROTEINS Primary 1st level of protein structure – Each protein has a unique primary structure, particular number & sequence of amino acids making up the polypeptide chain  20 different amino acids are used to build proteins  structure of a single generalised amino acid (main back bone) is the same, forms the backbone polypeptide chain  Different amino acids have different properties that effect the folding of a protein  Thus structure ultimately determines shape of a protein which determines function Secondary 2nd level of protein structure – ALPHA HELIX (twists) In 2nd level of the polypeptide chain are coiled or folded forming twists & corrugations  structure contributes to the proteins overall shape  Pleated sheet – where the chain folds back on itself or 2 regions of chain lay parallel to one another  Secondary structure results from hydrogen bonding between atoms along the polypeptide backbone  negatively & positively charged atoms are attracted to one another at regular intervals along the chain, causing parts of the protein to twist or fold back upon itself Tertiary 3rd level of protein structure tertiary structure, irregular loops & folds that give the protein its overall 3 dimensional shape  The irregular folding of tertiary structure results from inner reactions of R groups of amino acids  Polar forces also contribute to tertiary structure, hydrophilic or polar R groups may hydrogen bond with one another or turn outward & hydrogen bond with the surrounding water  Hydrophobic non polar R groups cluster on inside of the protein & away from water

Quaternary – 4th level of protein structure Some proteins consist of 2 or more polypeptide chians  results from the combination of 2 or more polypeptides sub-units  stabilised by same sorts of attractions that stabilise tertiary structure  Example; a protein with quaternary structure - Haemoglobin the red oxygen carrying protein of blood  2 Beta chain & 2 Alpha Chains of polypeptides a total of 4 chains make up each haemoglobin molecule

PROTEIN/AMINO ACID NUCLEIC ACIDS    

DNA and RNA Largest molecules in the body Contain C, O, H, N, and P Building block = nucleotide, composed of N containing base, a pentose sugar, & a phosphate group

DEOXYRIBONUCLEIC ACID (DNA)    

Four bases: - adenine (A), guanine (G), cytosine (C), and thymine (T) Double‐stranded helical molecule in the cell nucleus Provides instructions for protein synthesis Replicates before cell division, ensuring genetic

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Which bonds often bind different parts of a molecule into a specific three-dimensional shape? HYDOROGEN In the body, the majority of fluid is in which of the following fluid compartments? - INTRACELLULAR What level of protein synthesis is represented by the coiling of the protein chain backbone into an alpha helix? SECONDARY STRUCTURE The major extracellular cation is: SODIUM The major positive ion outside cells is SODIUM What happens to a patient's red blood cells if the patient is given a hypertonic IV solution? THE CELLS WILL CRENATE, OR SHRINK

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Carbohydrates and proteins are built up from their basic building blocks by the – REOMVAL OF A WATER MOLECULE BETWEEN EACH TWO UNITS The atomic number of an element – INDICATES THE NUMBER OF PROTONS Sucrose is a DISACCHARIDE A long chain of simple sugars - POLYSACCARIDE What is a chain of 25 amino acids called? POLYPEPTIDE Which of the following negatively charged particles in plasma is found in much smaller quantities in interstitial fluid? PROTEIN Proteins are classified as: ANIONS In a DNA molecule, the phosphate serves - TO HOLDS THE MOLECULER BACKBONE TOGETHER An organic molecule is CH4 A solution that has a pH of 2 is described as being - ACIDIC Amino acids joining together to make a peptide is a good example of a(n) SYNTHESIS What does CH4 mean? THERE IS ONE CARBON AND FOUR HYDROGEN ATOMS

THE CELL  The cell is the smallest living unit CELL - THEORY 1. Cell is basic structural & functional unit of living organisms 2. The organisms activity depends on the individual & collective activity of its cells 3. Biochemical activity of cells is dictated by specific sub-cellular structures (organelles) 4. Continuity of life has a cellular basis EUKARYOTIC CELLS  Contain DNA, surrounded by nucleus  have other membrane bound organelles - carry out specialized functions e.g. animals, plants, fungi

NUCLEUS, NUCLEAR MEMBRANE, NUCLEOLUS  NUCLEUS – Control centre, regulates all cellular activity, contains genetic material (DNA)  NUCLEAR ENVELOPE – porous membrane, allows substance in/out of nucleus  NUCLEOLUS – factory where RIBOSOMES are made PLASMA (CELL) MEMBRANE  GATEKEEPER, controls materials that go in/out of cell  Protects cell contents & is hydrophilic - loves water/polar  Provides receptors for hormones, enzymes, antibodies CYTOPLASM  Contains cytosol, organelles, inclusions  CYTOSOL – gel like fluid, contains H₂O, ions, organic molecules e.g. enzymes  Provides medium where chemical reactions occur  ORGANELLES (LITTLE ORGANS) – organised compartments,, specific structure & function e.g. mitochondria, endoplasmic reticulum (smooth & rough), golgi complex ER & RIBOSOMES ENDOPLASMIC RECTICULUM – Membrane channels that run through cytoplasm  provides surface area where chemical reactions take place  ROUGH ER – ribosomes attach to rough ER – make proteins to be secreted  SMOOTH ER – makes lipids, steroids & detoxifies drugs  RIBOSOMES – site of protein synthesis “work bench” GOLGI APPARATUS (pancake structure)  PACKAGES &TRANSPORTS PROTEINS  Inclusion in lysosomes or export out of the cell LYSOSOMES & PEROXISOMES  LYSOSOMES intercellular digestion (bacteria, damaged cell parts)  PEROXISOMES Enzymatic (oxidases) detoxification potentially harmful substances e.g. hydrogen peroxide MITOCHONDRIA  Site of most ATP (energy) production – power plant of cell MICROTUBULES & MICROFILAMENTS  Cytoskeleton- scaffolding of the cell  Hollow tubes made of protein for support/shape of cell  Allows coordinated movement of cells CENTROSOMES & CENTRIOLES CENTROSOMES – helps arrange microtubules in non-dividing cells  Forms mitotic spindles during cell division CENTRIOLES – help to make/regenerate flagella & cilia

CILIA & FLAGELLA  CILIA – hair like structures used for cell movement/ movement of materials across cell  FLAGELLA – whip like structures for cell movement e.g. sperm CELL DIVERSITY  200 different cell types in the body  cell shape determines specific functions  Most have same basic structure  Nucleus  Cytoplasm  Cell membrane

CELL MEMBRANE  Fluid mosaic model – mosaic of PROTEINS floating like icebergs in sea of LIPIDS  Protection via insoluble flexible barrier – protects cell from external environment  selective transport for nutrients/waste products

LIPIDS (MOSTLY PHOSPHOLIPIDS)  POLAR – phosphate contains heads HYDROPHILIC (water loving) face outwards to watery cytosol/extracellular fluid (extra – outside)  NON POLAR – fatty acid chain tails – HYDROPHOBIC – water fearing, face each other in membrane interior - Creates sandwich – phospholipid bilayer CELL MEMBRANE PROTEINS  2 types vital for membrane structure  INTERGRAL – glycoproteins, extend across phospholipid bilayer (go across)  PERIPHERAL – do not extend across bilayer – loosely attached to inner/outer surfaces, easily separated from membrane TRANSPORT/MOVEMENT  PASSIVE PROCESSES  E.G. simple diffusion, facilitated diffusion, osmosis – require KENETIC ENERGY (free energy – of motion) no energy output from cell - Facilitated diffusion - transported substances bind to carrier or pass through protein channels  FILTRATION – uses HYDROSTATIC pressure (no energy output from cell) e.g. glomerulus  SIMPLE DIFFUSION – solutes move D↓ (with) concentration gradient from H↑ solute concentration to L↓ area of concentration Molecules that can diffuse through cell membrane e.g. non-polar, lipid soluble molecules  ACTIVE PROCESSES  Requires energy in form of ADENOSINE TRIPHOSPHATE (ATP energy molecule) e.g. primary & 2nd active transport, bulk transport - Need (ATP), used to move molecules against concentration gradient

- Used for large molecules  ACTIVE TRANSPORT - energy driven process moves substances through cell membrane against concentration/electrical gradient - requires carrier proteins (called pumps)  SYSTEMS OF ACTIVE TRANSPORT - Symport system – 2 substances moved across membrane in same direction - Antiport system – 2 substances moved across membrane in opposite direction OSMOSIS  Movement of water across selectively permeable membrane from area of ↑ water concentration with ↓ solute concentration to area of ↓ water with ↑solute concentration  Osmolarity – total concentration of solute particles in a solution Process Simple Diffusion Facilitated Diffusion Osmosis Filtration

Energy Source Kinetic energy Kinetic energy Kinetic energy Hydrostatic pressure

Example Movement of O₂ through membrane Movement of glucose into cells Movement of H₂O in & out of cells Formation of kidney filtrate

BULK TRANSPORT (ACTIVE VESICULAR)  EXOCYTOSIS – removes substances from the cell A vesicle (sac) carries substances to plasma/cell membrane to be released e.g. neurotransmitters, hormones  ENDOCYTOSIS (endo – within) – brings substances into cell Segment of plasma/cell membrane surrounds substance & encloses it e.g. Phagocytosis (cell eating) FUNCTIONS OF CELL MEMBRANE PROTEINS

Membrane proteins (& glycoproteins) determine which function(s) a cell can Perform & the different types may include:

TISSUE  4 TISSUE TYPES  Connective tissue  Nervous tissue  Muscle Tissue  Epithelial tissue CONNECTIVE TISSUE - FUNCTIONS    

Binding & support (Connective) Protection (bone) Insulation (fat) Transportation (blood)

CONNECTIVE TISSUE CATEGORIES  Connective tissue proper - Loose (vascular), areolar, adipose, reticular & Dense & regular  Cartilage – 3 types – 1. Hyaline – nose/larynx, 2. Elastic – ear, 3. Discs knees joints  Bone – collagen fibres, supports/protects & provides muscle action, stores calcium/minerals/fats  Blood – red/white blood cells, transport of respiratory gases, nutrients & wastes CHARACTERISTICS  Mesenchyme as common tissue of origin  Varying degrees of vascularity – highly vascular/Avascular  Nonliving extracellular matrix consisting of ground substance (fluid/molecules) & fibres (collagen/elastic fibres) STRUCTUAL ELEMENTS  GROUND SUBSTANCE (matrix) – unstructured material, fills space between cells  Interstitial (tissue) fluid (cell)  Proteoglycans glycosaminoglycans (GAGs) molecules  Adhesion proteins – fibronectin & laminin  Functions as molecular sieve which nutrients diffuse between blood capillaries & cells  FIBRES – collagen, elastic, reticular  Collagen provides strength, ligaments/tendons  Elastic long thin fibres allow stretch  Reticular branched collagenous fibres form delicate networks  CELLS – fibroblasts, chondroblasts (cartlidge), osteoblasts, hematopoietic stem cell  Fibroblasts – connective tissue proper  Chondroblasts – cartridge  Osteoblasts – bone  Hematopoietic stem cells – blood – white blood cells, plasma, mast cell

CONNECTIVE TISSUE PROPER – LOOSE (3) 1. AREOLAR CONNECTIVE TISSUE - LOOSE– gel like matrix with all 3 connective tissue fibres  Fibroblasts, macrophages, mast cells (part of immune system)  Wraps/cushions organs

2. ADIPOSE CONNECTIVE TISSUE - LOOSE - matrix like areolar CT – collagen fibres make it tough, capillaries highly vascular - Reserves food stores, insulates against heat loss, supports/protects - Found under skin, around kidneys, abdomen, breast - Local fat deposits serve nutrient need

3.    

RETICULAR CONNECTIVE TISSUE - LOOSE Lose ground substance with reticular fibres Reticular cells lie in fibre network Forms soft internal; skeleton/stoma support other cell types Found in spleen, lymph nodes, bone marrow

1.    

DENSE REGULAR - CONNECTIVE TISSUE PROPER – avascular Parallel collagen fibres, few elastic fibres Major cell type – fibroblasts Attaches muscle to bone or other muscles, bone to bone Found in tendons, ligaments, aponeuroses

2.    

DENSE IRREGULAR – CONNECTIVE TISSUE PROPER Irregularly arranged collagen fibres with some elastic Major cell type – fibroblasts Withstands tension in many directions Found in dermis, fibres organ capsules

EPITHELIAL TISSUE

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Cellularity – composed almost entirely of cells Specialised contacts – form continuous sheets held together by tight junctions & desmosomes Polarity – apical & basal surfaces Avascular but innervated – contains no blood vessels but supplied by nerve fibres Regenerative – rapidly replaces lost cells by cell division

Simple

Stratified

SQUAMOUS – Single layer flattened cells, disc shaped nuclei & square cytoplasm -

FUNCTION – diffusion/filtration, friction reducing lining in lymphatic/cardiovascular systems Found in kidney glomeruli, lining of heart, blood vessels

CUBOIDAL - Single layer cube like cells, large spherical central nuclei -

FUNCTION – secretion & absorption Found in kidneys tubules, ducts & secretory portions of small glands, ovary surface

COLUMNAR - SIMPLE – single layer of tall cells oval nuclei many contain cilia -

FUNCTION – secretion & absorption Found – Ciliated – line small bronchi, uterine tubes – Non-ciliated – line digestive tract & gallbladder

SIMPLE SQUARMOUS EPITHELIA

SIMPLE CUBODIAL EPITHELIA

SIMPLE COLUMNAR EPITHELIA

PSEUDOSTRATIFIED COLUMNAR    

Single layer cells different heights; some unable to reach free surface Nuclei are seen at different layers FUNCTION – secretion & propulsion of mucus FOUND- in male sperm-carrying ducts (non-ciliated) & trachea (ciliated)

PSEUDOSTRATIFIED COLUMNAR

STRATIFIRD SQUAMOUS  Thick membrane several layers of cells  FUNCTION – protection of underlying areas subjected to abrasion  Forms external part of skins epidermis (keratinized cells), lining of Esophagus, mouth, vagina (nonkeratinized)

EPITHELIA: STRATIFIED CUBOIDAL & COLUMNAR  STRATIFIED CUBOIDAL - Quite rare in the body  Found in some sweat & mammary glands  Typically two cell layers thick  STRATIFIED COLUMNAR - Limited distribution in body  Found in pharynx, male urethra, & lining some glandular ducts  Also occurs at transition areas between two other types of epithelia EPITHELIAL Membranes Epithelial membranes consist of two tissue types:  Epithelial  Connective Tissue

 CUTANEOUS MEMBRANES - Covers body – Skin

MUCOUS MEMBRANES - lines body cavities open to the exterior (e.g., digestive and respiratory tracts)

SEROUS MEMBRANES - moist membranes found in closed ventral body cavity

INTERGUMENTARY SYSTEM SKIN  3 Major regions 1. -

EPIDERMIS – outermost superficial region Keratinized stratified squamous epithelium – 4 distinct cell types 4/5 layers Cells – keratinocytes, melanocytes, merkel cells & Langerhans cells Outer portion of skin exposed to external environment – functions as protection

2. DERMIS – middle region - 2nd major skin region – strong flexible connective tissue Cells include – fibroblasts, macrophages, mast cells, white blood cells Composed of 2 layers – papillary & reticular - Reticular layer – 80% thickness of skin, collagen fibres add strength/resiliency to skin, elastin fibres provide stretch-recoil properties - Papillary layer - Areolar connective tissue with collagen/elastic fibres, superior surface contains – pegs(dermal papillae – contain capillary loops, free nerve endings) sensory receptors 3. Hypodermis – (superficial fascia) deepest region - subcutaneous layer deep in the skin - composed of adipose & areolar connective tissue

4 CELLS OF THE EPIDERMIS - KERATINOCYTES – produce fibrous protein keratin - MELANOCYTES – produce brown pigment melanin - LANGERHANS CELLS – epidermal macrophages help activate immune system - MERKEL CELLS – FUNCTION – touch receptors with sensory nerve endings LAYERS OF THE EPIDERMIS - STRATUM BASALE (BASALLAYER) Deepest layer attached to dermis Consists of single row of youngest keratinocytes Cells undergo rapid division hence called stratum germinativum -

STRATUM SPINOSUM (PRICKLY LAYER) Cells contain weblike system of filaments attached to desmosomes Melanin granules & Langerhans cells abundant in this layer

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STRATUM GRANULOSUM (GRANULAR LAYER) Thin 3 – 5 cell layers which drastic changes in Keratinocyte occurs Keratohyaline & lamellated granules accumulate in cells of this layer

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STRATUM LUCIDUM (CLEAR LAYER) Thin transparent band superficial to stratum granulosum Consists of few rows of flat, dead keratinocytes Present only in thick skin

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STRATUM CORNEUM (HORNY LAYER) Outermost layer of keratinized cells, accounts for ¾ of epidermal thickness Functions – waterproofing, protection from abrasion/penetration Rendering body relatively insensitive to biological, chemical, physical assaults

SKIN COLOUR - 3 Pigments contribute to skin colour - MELANIN – yellow/reddish, brown/black pigment responsible for dark skin colours Local accumulations of melanin result in freckles, pigmented moles - CAROTENE – yellow/orange pigment seen in palms, soles of feet - HEMAGLOBIN – reddish pigment responsible for pinkish hue of skin SWEAT GLANDS – 2 TYPES - ECCRINE SWEAT GLANDS – (normal sweat glands) found in palms, soles of feet, forehead - APOCRINE SWEAT GLANDS (arm pit, genital area) found in axillary & anogential areas produce diff smell – pheromones SWEAT GLANDS - CERUMINOUS GLANDS – modified APOCRINE glands – in ear canal, secrete cerumen (earwax) - MAMMARY GLANDS – secrete milk SEBACEOUS GLANDS - Simple glands found all over body, soften skin when stimulated by hormones, secrete oil called SEBUM (antibacterial properties)

TISSUE    

THE THREE MAIN COMPONENTS OF CONNECTIVE TISSUE ARE – GROUND SUBSTANCE, FIBRES, & CELLS MUSCLE IS NOT CONSIDERD CONNECTIVE TISSUE STRATIFIED EPITHELIA ARE COMMONLY FOUND IN AREAS OF HIGH ABRASION CELL TYPES LIKELY TO BE SEEN IN AREOLAR CONNECTIVE TISSUE INCLUDE ALL EXCEPT: OSTEOCYTES