6. Bones & Skeletal Tissue

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

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.

Which pathway correctly identifies the relationship between bone cells?

Which of the following would you expect to be prominent in osteoclasts?

a. Golgi apparatus

b. Lysosomes

c. Microfilaments

d. Exocytosis

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

Osteocytes residing in lacunae of osteons of healthy compact bone are located quite a distance from the blood vessels in the central canals, yet they are well nourished. How can this be explained?

a. Why are fractures most common in elderly individuals?

b. Why are greenstick fractures most common in children?

Bone remodeling in adults is regulated and directed mainly by:

a. Growth hormone

b. Thyroid hormones

c. Sex hormones

d. Mechanical stress

e. PTH

How does the structure of an osteocyte allow communication with adjacent cells?

What nutritional factors are essential for normal bone growth and maintenance?

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