Chapter 9
 Skeletal System - Notes
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 1. Name and describe the five ways that the skeletal system contributes to homeostasis and quality of life.

     - support - providing proper positioning so weak or soft organs can function
     - protection - preventing damage and distortion so weak or soft organs can function
     - movement
          - providing stable attachment sites for muscles provides effective muscle action
          - serving as levers modify the force, speed, and direction of muscle shortening to produce varied motions for complex life activities
     - mineral storage - supplying adequate minerals to all body cells in spite of variations in dietary intake and mineral losses (e.g., urine, perspiration)
     - blood cell formation - producing blood cells to replace blood cells as fast as they die to maintain adequate levels of blood cells

 2. Describe the effects of aging on bone cells.

     - no change

 3. Describe the age changes in the proportions of materials (i.e., protein and minerals) composing bone matrix and describe the effects from these changes.

     - decrease in protein:mineral ratio
     - effects = incr. brittleness -> incr. risk of traumatic fractures but retains good strengththroughout life

 4. Describe the timing and the general nature of age changes in the quantity of bone matrix and describe the effects from these changes.

     - decr. trabecular bone starting about age 20
          - thinner, weaker, less connected, some disappear (irreplaceable)
     - decr. cortical bone starting about age 40
          - overall thinning of cortex, incr. osteon junctions, incr. gaps among osteons -> decr. strength
          - slow until age 50, then faster
     - effects = decr. strength -> incr. risk of traumatic fractures but retains good strengththroughout life

 5. Describe the effects of menopause on bone matrix loss including the reason for the effects, the different effects on trabecular and cortical bone, common fractures that result, and the results from those fractures.

     - very great decr. trabecular bone from very great decr. estrogen
     - greater decr. in trabecular bone than in cortical bone -> incr. vertebral and hip fractures
     - results = pain, disability, infection, expense, immobility (clots, bed sores, pneumonia, faster matrix loss, muscle deterioration, etc. from lack of exercise)

 6. Name five methods for minimizing bone loss,

     - maintain ample exercise, calcium, vitamin D, & estrogen; avoid smoking and stomach antacids that contain aluminum; avoid excesses in alcohol, caffeine, phosphates (e.g., carbonated beverages), corticosteroids, dietary fiber, dietary protein

 7. Define osteoporosis and distinguish between the two types of osteoporosis based on age of onset, main contributing factors, and gender differences.

     - osteoporosis = bone disease -> hollow, thin, porous bone matrix
     - Type I = post-menopausal osteoporosis from great decr. estrogen in late 40s and 50s
          - almost always in women
     - Type II = senile osteoporosis from great decr. kidney vitamin D activation after age 60 and from decr. intestinal response to vitamin D
          - 2:1 ratio in  women: men
 
 8. Name and describe the effects from vertebral fractures caused by osteoporosis.

     - pain, decr. mobility, decr. height, altered posture, decr. respiration, social, psychological, economic

 9. Name and describe the effects from hip fractures caused by osteoporosis.

      - decr. mobility, disability (decr. ADLs), institutionalization, complications (clots, pneumonia, bed sores, infections, faster matrix loss, muscle deterioration, etc. from less exercise), social, psychological, economic

10. Name the four most important methods (ample exercise, calcium, vitamin D, & estrogen) plus two other methods for reducing the effects of osteoporosis on bone matrix.

     - same as for maintaining bone matrix

11. Name two main ways to reduce the incidence of fractures for those who have weakened bones from osteoporosis.

     - avoid heavy lifting
     - reduce falls

12. Describe age changes and effects from age changes in immovable joints.

     - fibrous tissue and interlocking bones -> no movement for maximum support and protection (e.g., skull sutures)
     - age changes = fibrous material and increased bone
     - effects = stronger and less movable

13. Describe age changes and effects from age changes in slightly movable joints.

     - cartilage between the bones, ligaments join bones -> slight movement for support, cushioning, slight movement
          - hyaline cartilage between ribs and sternum for breathing
          - fibrocartilage between vertebrae for support, smooth curves cushioning)
     - age changes =
          - 1. stiffer cartilage (cross-linking, calcification)
          - 2. stiffer and shorter ligaments (cross-links)
          - 3. nucleus pulposus -> weaker support
     - effects = (1) stiffer movement and (2) decr. ROM and (3) decreased support (height of vertebrae) (cosmetic, affects breathing)

14. Name and describe age changes and effects from age changes in movable joints.

     - functions = easy movement over a limited range
          - range of motion limited by ligaments and bone shapes
     - synovial membrane - incr. fibers and cross-links, decr. # of blood vessels ->
           (1) stiffer
           (2) less elasticity
           (3) decr. fluid turnover for cartilage nourishment
     - synovial fluid = OK (no significant changes)
     - cartilage = OK (no significant changes)
     - capsule and ligaments = incr. cross-links (begins about age 20) ->
          (1) shorter
          (2) stiffer
          (3) decr. elasticity
     - effects = 1. stiffer movement, and (2) decr. ROM

15. Describe the effects of exercise on the effects of aging of joints.

     - exercise slows rate of stiffening and rate of decr. ROM

16. Rank arthritis among diseases of the elderly.

     - most common disease among elderly people
     - causes most physician visits and bed-days

17. Describe the effects of osteoarthritis on joint structure and functions.

     - cartilage breakdown (thinner, weaker, rougher, softer)
          - decr. cushioning, smoothness
         - incr. bone formation (osteophytes) and possible fusion of bones
      - rougher edges, edges collide ->
           1. pain
           2. stiffness
           3. decr. ROM (including from joint fibrosis and bone fusion)
           4. pinched spinal nerves

18. Describe the effects of rheumatoid arthritis on joint structure and functions.

     - cartilage breakdown (thinner, weaker, rougher, softer)
          - decr. cushioning, smoothness
     - bone destruction
          - loss of joint structural integrity and possible fusion of bones
     - soft scar-like pannus causes additional joint destruction
     - effects
          1. pain
          2. stiffness
          3. decr. ROM (including from joint fibrosis and bone fusion)
          4. joint dislocation and deformity

19. List and describe treatments for OA and for RA.

     - slow progress of disease, relieve pain, reduce disability
     - medications to reduce pain and inflammation, exercise regimens, physical therapy, surgery

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© Copyright 1999 - Augustine G. DiGiovanna - All rights reserved.
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