Bone Responses

Question 1

3 zones of bone fro epiphysis to metaphysis
Cell activity
Blood supply
Which is weakest part of physis.

Answer 1

Cells mature from epiphysis –> metaphysics
•Reserve zone – closest to epiphysis. Cells produce and store cartilaginous matrix. Blood supply is poor and cells do not actively divide.
•Proliferative zone – cells synthesize matrix, divide, and are stacked in columns. Activity produces longitudinal growth. Has best blood supply, both for nutrition and to provide hormonal signals for growth.
•Hypertrophic zone – chondrycytes are large. Prepares matrix for calcification. The cells are metabolically active despite poor blood supply (rely on anaerobic metabolism). Weakest part of physics.

Question 2

What is soft callus made of?

Answer 2

Osteoid, cartilage, collagen

Question 3

Guidelines for bone mineral analysis (7)

Answer 3

• Postmenopausal women
• Men >65 or w/ hypogonadism
• Women w/ hx of prolonged hormone replacement therapy
• Vertebral deformities
• Primary hyperparathyroidism
• Long-term glucocorticoid therapy
• Medication for osteoporosis