10-16-2002, 02:55 AM
panicked
Here is the kaplan question with explanations. I agree with their pick, but I also think that B and possibly E can be correct. Please read the question and then come back to my argument:
-B and E can also be plausible since if the patient has low V-D, then he will produce more parathyroid hormone. Therefore, osteoclast activity should increase, and the tubacular formations should decrease because of the osteoclasts. If sever enough, we should even see fibrosis on the marrow (brown fibrosis due to hyperparathyrodism)
What do you think?
Thanks
Q. A strict vegetarian is not getting sufficient vitamin D in his diet, and he develops osteomalacia. This
disease is characterized by which of the following changes in his bones?
A. Decreased osteoblasts
B. Increased osteoclast activity
C. Increased osteoid
D. Marrow fibrosis
E. Sparse bony trabeculae
Explanation:
The correct answer is C. The hallmark of osteomalacia is widened osteoid seams. Although the
trabeculae are normal in number and size, they do not mineralize effectively, and the rim of
uncalcified osteoid is much larger than normal.
Osteoclast activity is normal in osteomalacia. Increased osteoclast activity (choice B) is
typical of hyperparathyroidism and Paget's disease of bone.
There are increased numbers of osteoblasts in osteomalacia (compare to choice A), which lay
down increased quantities of osteoid in an effort to strengthen the bone. Unfortunately, the
increased osteoid is not mineralized and the bone remains soft and weak.
The bone marrow space is normal in osteomalacia. Marrow fibrosis (choice D) is more typical of
hematopoietic disorders, although hyperparathyroidism may also lead to bone marrow fibrosis.
Although poorly mineralized, the bony trabeculae are of normal abundance in osteomalacia.
Sparse trabeculae (choice E) is characteristic of osteoporosis.
Here is the kaplan question with explanations. I agree with their pick, but I also think that B and possibly E can be correct. Please read the question and then come back to my argument:
-B and E can also be plausible since if the patient has low V-D, then he will produce more parathyroid hormone. Therefore, osteoclast activity should increase, and the tubacular formations should decrease because of the osteoclasts. If sever enough, we should even see fibrosis on the marrow (brown fibrosis due to hyperparathyrodism)
What do you think?
Thanks
Q. A strict vegetarian is not getting sufficient vitamin D in his diet, and he develops osteomalacia. This
disease is characterized by which of the following changes in his bones?
A. Decreased osteoblasts
B. Increased osteoclast activity
C. Increased osteoid
D. Marrow fibrosis
E. Sparse bony trabeculae
Explanation:
The correct answer is C. The hallmark of osteomalacia is widened osteoid seams. Although the
trabeculae are normal in number and size, they do not mineralize effectively, and the rim of
uncalcified osteoid is much larger than normal.
Osteoclast activity is normal in osteomalacia. Increased osteoclast activity (choice B) is
typical of hyperparathyroidism and Paget's disease of bone.
There are increased numbers of osteoblasts in osteomalacia (compare to choice A), which lay
down increased quantities of osteoid in an effort to strengthen the bone. Unfortunately, the
increased osteoid is not mineralized and the bone remains soft and weak.
The bone marrow space is normal in osteomalacia. Marrow fibrosis (choice D) is more typical of
hematopoietic disorders, although hyperparathyroidism may also lead to bone marrow fibrosis.
Although poorly mineralized, the bony trabeculae are of normal abundance in osteomalacia.
Sparse trabeculae (choice E) is characteristic of osteoporosis.