1. Remodeling of skeletal structures
Bone tissue is constantly being torn down and built up
About 10% of bone is replaced every year in an adult skeleton

2. bone formation
bone reabsorption
osteoblasts
osteoclasts

3. Hormonal effects osteoblasts osteoclasts Calcitonin (CT) from thyroid
bone formation
bone reabsorption
osteoblasts
osteoclasts
Calcitonin (CT) from thyroid
Parathyroid hormone (PTH) from parathyroid

4. Age effects Before age 25 osteoblasts osteoclasts bone reabsorption
bone formation
bone reabsorption
osteoblasts
osteoclasts
Before age 25

5. Age effects Age 25-50 osteoblasts osteoclasts bone formation
bone reabsorption
osteoblasts
osteoclasts
Age 25-50

6. Age effects Age 50-120 osteoblasts osteoclasts bone formation
bone reabsorption
osteoblasts
osteoclasts
Age

7. Stress increases bone density
Stress effects
bone formation
bone reabsorption
osteoblasts
osteoclasts
Stress increases bone density

8. can alter orientation & size of
Direction of stress
can alter orientation & size of
of osteons

9. Increasing
bone stress can
reduce or eliminate
age-related bone loss

10. Space travel
decreases stress
& increases bone loss

11. Too much stress . . .