The Skeletal System I. Objectives

 

THE SKELETAL SYSTEM I. OBJECTIVES 1. To examine examine the skeleton skeleton relang relang to physica physicall characteris characteriscs cs to funcon funcon.. 2. To idenfy idenfy the the bones bones compos composing ing the human human skeletal skeletal system system.. 3. To understa understand nd the relaons relaonship hip of the internal internal structu structure re of bone to its funcon funcons. s. II. MATERIALS Charts, Illustraons and references III. PROCEDURES Study the model of the human skeleton. Using the references and charts, idenfy the bones in each of the following groups: 1. Skull Skull (fro (front nt and and side side views views)) 2. Inferi Inferior or sur surfac face e of of th the e skull skull 3. Vertebral Vertebral column column (note (note disnguis disnguishing hing features features of of vertebrae vertebrae per region) region) 4. Scapula 5. Thorax Thorax (ante (anterio riorr and poste posterio riorr view viewss 6. Rib 7. Up Uppe perr ext extre remi mity ty 8. Fo Fore rear arm m and and ha hand nd 9. Pelvic bo bone 10. Bones Bones of the the leg 11. Bones Bones of the foot foot A. Major Bones of the Body 1. Using the references, idenfy whether the following bones are a part of the axial or appendicular skeletonAxial by wring the  correct region on the provided blank.  blank.   A. Sternum Skeleton B. Humerus Appendicular Skeleton C. Skull Axial Skeleton D. Ribs Axial Skeleton E. Femur Appendicular Skeleton F. Carpals Appendicular Skeleton Appendicular Skeleton G. Clavicle 2. Provide one general funcon of the axial skeleton that is not a funcon of the appendicular skeleton. one general function of the axial skeleton that is not a function of the appendicular

skeleton, it serves to protect the brain, spinal cord, heart, and lungs. It also serves as the

 

attachment site for muscles that move the head, neck, and back, and for muscles that act across the shoulder and hip joints to move their corresponding limbs.

B. Gross Anatomy of Bone 1. Name one notable structural feature found in compact bone but not in spongy bone. One notable structural feature found in compact bone is they can withstand compressive

forces. 2. Name one notable structural feature found in spongy bone but not in compact bone. (2 point)

One notable structure feature found in spongy bone is they are not usually arrange in concentric circles.

3. Complete the table below on bone shapes Bone Shape Descripon Long one that is cylindrical and is longer than

it is wide.

Short

Flat

Irregular

Sesamoid

one that is cube-like in shape, being approximately equal in length, width, and thickness. They provide stability and support as well as some limited motion somewhat of a misnomer because, although a flat bone is typically thin, it is also often curved. a small, round bone that, as the name suggests, is shaped like a sesame seed. form in tendons, the sheaths of tissue that connect bones to muscles, where a great deal of pressure is generated in a joint.  protect tendons by helping them overcome compressive forces. Sesamoid  bones vary in number and placement

Examples

arms (humerus, ulna, radius) legs (femur, tibia, fibula), as well as in the fingers (metacarpals,  phalanges) and toes (metatarsals,  phalanges). carpals of the wrists and the tarsals of the ankles

cranial (skull) bones, the scapulae (shoulder   blades), the sternum (breastbone), and the ribs vertebrae, hip bones, and several skull  bones

 patella

   

from person to person but are typically found in tendons associated with the feet, hands, and knees. 4. Name the bone feature that best matches each provided descripon. (10 points) A. Large rough surface of a bone Tuberosity B. Short, sharp projecon Spine  C. Hole through bone Foramen D. Flat surface on a bone Facet E. Prominent rounded projecon Head C. Microscopic Anatomy of Bone 1. Dene each of the following compact compact bone structures in one sentenc sentence e each: A. Canaliculi thin empty channels that again prevent the solid, mineralized extracellular material from crushing the osteocyte extensions B. Lacuna cell-shaped empty spaces that prevent the solid, mineralized extracellular material of bone from crushing the osteocytes C. Osteon composed of concentric rings of calcified matrix called lamellae D. Central canal contains blood vessels, nerves, and lymphatic vessels

IV. QUESTIONS FOR RESEARCH: 1. Outline the sequence of events in embryonic growth of bone. There are two types of bone ossification, intramembranous and endochondral, each of  these the se proces processes ses begins begins with with a mesenc mesenchym hymal al ti tissu ssuee precur precursor sor.. Intram Intramemb embran ranous ous ossification directly converts the mesenchymal tissue to bone and forms the flat bones of the skull, clavicle, and most of the cranial bones. Endochondral ossification begins with mesenchymal tissue transforming into a cartilage intermediate, which is later  replaced by bone and forms the remainder of the axial skeleton and the long bones. 2. List and describe the dierent fontanels, sutures and sinuses of the skull. skull .

FONTANELS 

Anterior fontanelle (also called soft spot). This is the  junction where the 2 frontal and 2 parietal  bones meet. The anterior fontanelle remains soft until about 18 months to 2 years of age. Doctors can assess if  there is increased

intracranial pressure

SUTURES 



Metopic suture. This extends from the top of the head down the middle of the forehead, toward the nose. The 2 frontal  bone plates meet at the metopic suture. Coronal suture. This

SINUSES 

Frontal sinuses: The right and left frontal sinuses are located in the center of the forehead (frontal  bone) just above each eye.

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Maxillary sinuses: These are the largest of the

 



 by feeling the anterior fontanelle. Posterior fontanelle. This is the junction of the 2 parietal bones and the occipital  bone. The posterior fontanelle usually closes first, before the anterior fontanelle, during the first several months of an infant's life.

extends from ear to ear. Each frontal bone plate meets with a  parietal bone  plate at the 



coronal suture. Sagittal suture. This extends from the front of the head to the back, down the middle of the top of the head. The 2 parietal  bone plates meet at the sagittal suture. Lambdoid suture. This extends across the back of the head. Each  parietal bone  plate meets the occipital bone  plate at the lambdoid suture.

sinuses and are located behind the cheekbones near the maxillae, or upper  jaws. 

Sphenoid sinuses: The sphenoid sinuses are located in the sphenoid bone near the optic nerve and the pituitary gland on the side of the skull.



Ethmoid sinuses: The ethmoid sinuses are located in the ethmoid bone, which separates the nasal cavity from the  brain. These sinuses aren’t single sacs but a collection of 6 to 12 small air cells that open independently into the nasal cavity. They’re divided into front, middle, and rear groups.

3. Dierenate between male and female pelvis. For male pelvis its heavy and thick while for female its light and thin 4. Discuss the stages of bone healing.

 

Stages of bone healing are inflammatory, reparative and remodeling Inflammatory stage- is when a bone breaks, the body sends out signals for special cells to come to the injured area. Some of these special cells cause the injured area to become inflamed (red, swollen, and painful). This tells the body to stop using the injured part so it can heal. callus (a type of soft Reparative Reparat ive stage- starts within about a week of the injury. A soft callus (a  bone) replaces the blood clot that formed in the inflammatory stage. The callus holds the  bone together, but isn't strong enough for the body part to be used. Remodeling stage-  starts around 6 weeks after the injury. In this stage, regular bone replaces repla ces the hard callus. callus. If you saw an X-ray X-ray of the healing bone, it would look uneven. But over the next few months, the bone is reshaped so that it goes back to looking the way it did before the injury. 5. Dene the following: (8 points) a. Craniotomy Surgical procedure in which part of the cranium is removed. It may be performed to remove a blood clot, c lot, a brain tumor, or a sample of brain tissue for biopsy. b. Scoliosis mostt common mos common of the abnormal abnormal curves curves,, is a lat latera erall bendin bending g of the verteb vertebral ral column, usually in the thoracic region c. Lordosis sometimes called hollow back, is an increase in the lumbar curve of the vertebral column. May result from increased weight of the abdomen as in pregnancy or  extreme obesity, poor posture, rickets, osteoporosis, or tuberculosis of the spine d. Kyphosis is a cr crea ease se in the the thor thorac acic ic cu curv rvee of th thee ve vert rteb ebra rall co colu lumn mn th that at pr prod oduc uces es a “hunchback” look  e. Spin ina a bi bida a congenital defect of the vertebral column f. Sinusis An inflammation of the mucosal surface of the paranasal sinuses g. Oste Osteo oporo porosi siss a common disease of the bones & is often silent until a fracture occurs, making screening important h. Arthris An inflammation of a joint or joints 6. Tabulate the general and specic dierences between male and female skeleton. Point of Comparison Greater (false) pelvis Pelvic brim (Pelvic inlet)

Female

Male

Shallow Wide and more oval

Deep Narrow shape

Pubic arch

Gre reat ater er than than 90 an angl glee

Les Less than han 90 angl anglee

and

heart

 

Less vertical

Ilium Iliac fossa Iliac crest Acetabulum Obturator foramen

Less curved Small and anteriorly Oval

More vertical More curved faces Large and laterally Round

faces

  7. Illustrate and describe the dierent types of bone fractures. Type of Bone Fracture Greenstick  fracture

Descripon

The bone partly fractures on one side but does not break completely,  because the rest of the bone can bend.

Open (Compound) Fracture Pottt Frac Pot Fractur turee Coll Co lles es Frac Fractu ture re Comminuted fracture Impacted Fracture  

 broken ends of the bone protrude through the skin. Conversely, a closed (simple) fracture does not break the skin Fractu Fracture re of of the the dist distal al end end of of tthe he late lateral ral leg bone bone (fibu (fibula) la),, with with seri serious ous inj injury ury of the distal Frac Fractu ture re tibial o off the thearticulation. dist distal al end end of of the the late latera rall fore forear arm m bone bone (ra (radi dius us)) in whi which ch the distal fragment is displaced posteriorly An impact shatters the bone into many pieces. One end of the fractured bone is forcefully driven into the interior of  the other.