p158, 1-27; OMIT 7, 9, 15, 17, 18, 22, 23

1. Name three functions of the skeletal system.Here are five, boss. (see p116-117)- Forms the body’s internal structural framework (i.e. provides support)- Anchors skeletal muscle- Protects/shields vital organs (the skull, the thorax, the pelvis, oh my!)- reservoir (storage) for calcium and fats- blood cell formation

2. What is the anatomical name for the shaft of a long bone? …for its ends? What is yellow marrow? How do spongy and compact bone look different?- bone shaft = diaphysis- bone end = epiphysis- yellow marrow is fat tissue. - spongy bone is less dense than compact bone and appears—there’s seriously no better word to describe it—spongy. (It’s made of an irregular network of collagen fibers surrounded by a calcium matrix. )- compact bone is very dense and appears solid (it contains internal spaces of microscopic size and narrow channels that contain blood vessel and nerves.)

3. Why do bone injuries heal much more rapidly than injuries to cartilage?Bone is highly vascular and thus heals rapidly. Cartilage has poor vascularization so nutrition is supplied to chondrocytes only by diffusion. Compared to other connective tissues, cartilage heals very slowly and poorly.

4. Compare and contrast the role of PTH (hormone) and mechanical forces acting on the skeleton in bone remodeling.

Parathyroid hormone (PTH, also called parathormone or parathyrin) promotes calcium homeostasis in the blood. It determines when or if bone is to be broken down or formed in response to need for more or fewer calcium ions in the blood. If blood calcium levels drop, PTH activates osteoclasts which—loaded with lysosomes—break down bone, releasing calcium. Mechanical forces applied to bones dictate where calcium can safely be removed or where more calcium salts should be deposited to maintain bone strength.

5. Define fracture. Which fracture types are most common in the elderly? Why are greenstick fractures more common in children?A fracture is simply a break in a bone. Compression and comminuted fractures are most common in older people. Greenstick fractures are more common in children because their bones’ matrices contain relatively more collagen and are more flexible.

6. Name the three major parts of the axial skeleton.Skull, thorax, vertebral column.

7x

8. What bones are connected by the coronal suture? …by the sagittal suture?Coronal: frontal & parietalsSagittal: two parietals

9.x

10. What facial bone forms the chin? The cheekbone? The upper jaw? The bony eyebrow ridges?The chin – mandible

Cheekbone – zygomaticUpper jaw – maxillaeBony eyebrow ridges - frontal bone

11. Name two ways in which the fetal skull differs from the adult skull.The fetal skull has:

- much larger cranium-to-skull size ratio- foreshortened facial bones- unfused membranous areas (fontanelles)

12. Name the five major regions of the vertebral column.Cervical (7 vertebrae); Thoracic (12); Lumbar (5); Sacral (5 fused vertebrae); Coccygeal (4 fused)

13. Diagram the normal spinal curvatures, and then the curvatures seen in scoliosis & lordosis.Kyphosis is excessive curvature of the upper spineLordosis is excessive curvature of the lower spine (think lower-dosis)Scoliosis is a lateral curvature.

14. What is the function of the intervertebral discs? To cushion shocks to the head, and to allow smooth movement of the vertebral column.

15x

16. What is a true rib? …a false rib? Is a floating rib a true or a false rib? Why are floating ribs easily broken?True rib: attached directly to the sternum by its own costal cartilage.False rib: Attached to sternum indirectly or not at all.A floating rib is a false rib. They are easily broken because they have no anterior (sternal) attachment (direct or indirect) and thus have no anterior reinforcement.

17x18x

19. The major function of the shoulder girdle is to provide flexibility. What is the major function of the pelvic girdle?Bearing weight! (strength!)

20. What bones make up each hip bone or coxal bone? Which of these is the largest? Which has tuberosities that we sit on? Which is the most anterior?The ilium, ischium and pubis make up each os coxa (hip bone). The ilium is the largest. The ischium has tuberosities that we sit on (“butt loops” = ischial tuberosities!) The pubis is the most anterior.

21. List three differences between the male and the female pelvis.The female pelvis is lighter, broader, shallower, with a larger inlet and outlet, and a shorter an straighter sacrum. For myself though, the easiest way to tell the difference between a male and female pelvis is by examining the pubic arch, the angle formed by the two medial sections of the ischia; A female’s pubic arch (on the left, below) is obtuse, greater then 90˚. A male’s pubic arch (on the right) is acute, less than 90˚, and has a broader pubic arch

female > 90˚ pubic arch male < 90˚ pubic arch

22x23x

24. Compare the amount of movement possible in synarthroitc, amphiarthrotic, and diarthrotic joints. Relate these terms to the structural classification (fibrous, cartilaginous, synovial) of joints.

- Synarthrotic: Essentially immovable (generally fibrous)- Amphiarthrotic: Slightly movable (generally cartilaginous)- Diarthrotic: Freely movable (synovial)

25. Describe the structure of a synovial joint.The articulating ends of bones in a synovial joint are covered with articular cartilage and are separated by a cavity that contains synovial fluid. Synovial joints are enclosed by a fibrous connective tissue capsule lined with a smooth synovial membrane. Reinforcing ligaments may reinforce the fibrous capsule, and bursae may cushion tendons where they contact bone.

26. Define arthritis. What type of arthritis is most common in the elderly? What type is believed to result from the immune system’s attack on one’s own joint tissues?Arthritis is inflammation of the joints. Degenerative arthritis (osteoarthritis) is the type most common in the elderly (due to wear & tear on joints that accompanies increasing age and use.) Rheumatoid arthritis is believed to be autoimmune.

27. List two factors that keep bones healthy. List two factors than can cause bones to become soft or to atrophy.

- Bones stay healthy with physical stress/use (most important) and proper diet (e.g. calcium). - Bones become soft or atrophy with disuse, hormone imbalances, and loss of stimulation.