Question

unit 2 - challenge 2.2: the skeletal system
what characterizes osteoporosis at the histological level?
a.) increase in the number and size of trabeculae in spongy bone
b.) reduction in the thickness of compact bone and the number and size of trabeculae in spongy bone
c.) formation of haphazard new bone
d.) increase in osteoblastic activity

Explanation:

Osteoporosis is a condition where bone density decreases. At the histological level, this involves a reduction in the thickness of compact bone (the dense outer layer of bone) and a decrease in the number and size of trabeculae (the small, rod - like structures in spongy bone). Option a is incorrect as it suggests an increase in trabeculae which is the opposite of what happens in osteoporosis. Option c (formation of haphazard new bone) is more characteristic of other bone disorders like Paget's disease. Option d (increase in osteoblastic activity) would lead to bone formation, but in osteoporosis, osteoclastic (bone - resorbing) activity is relatively higher than osteoblastic (bone - forming) activity.

Answer:

B. Reduction in the thickness of compact bone and the number and size of trabeculae in spongy bone