Explain why a person who is wheelchair-bound or bed-bound often has very low bone mass, especially in his or her legs.

How could diseases of the kidney, skin, and/or intestines cause diseases of the bone?

How could a disease that affects primarily cartilage impact bone growth and bone formation?

It used to be common practice in surgical fracture repair to strip and remove the periosteum. Now, however, surgeons take great care to avoid damaging the periosteum. Explain why, and describe what would likely happen to bone healing with the periosteum missing.

Explain why young men who take anabolic steroids (which mimic the actions of testosterone) often display stunted growth and have an overall shorter stature.

Lucy Dupre is a 2-year-old girl living in northern Canada. You notice that her growth seems abnormally slow and she has exhibited signs of weakened bones, including fractures. Her parents admit they have not supplemented her diet with vitamin D, as they feel that any supplementation is 'unnatural' and 'not organic.' Explain why Lucy is having problems with her bones and bone growth.