Describe the process of new bone formation in an adult bone. Use the terms "osteoid seam" and "calcification front" in your discussion.

Bone remodeling in adults is regulated and directed mainly by:

a. Growth hormone

b. Thyroid hormones

c. Sex hormones

d. Mechanical stress

e. PTH

The disorder in which bones are porous and thin but bone composition is normal is

a. Osteomalacia

b. Osteoporosis

c. Paget's disease

Describe in proper sequence the events of endochondral ossification in a long bone.

As we grow, our long bones increase in diameter, but the thickness of the compact bone of the shaft remains relatively constant. Explain this phenomenon.

a. Why are fractures most common in elderly individuals?

b. Why are greenstick fractures most common in children?

Why do you think wheelchair-bound people with paralyzed lower limbs have thin, weak bones of the leg and thigh?

Mrs. Abbruzzo brought her 4-year-old daughter to the doctor, complaining that she didn't 'look right.' The child's forehead was enlarged, her rib cage was knobby, and her lower limbs were bent and deformed. X rays revealed very thick epiphyseal plates. Mrs. Abbruzzo was advised to increase dietary amounts of vitamin D and milk and to get the girl outside to play in the sun. Considering the child's signs and symptoms, what disease do you think she has? Explain the doctor's instructions.

What would a long bone look like at the end of adolescence if bone remodeling did not occur?