Chapter 79 Parathyroid Hormone, Calcitonin, Calcium and Phosphate Metabolism, Vitamin D, Bone, and Teeth

Chapter 79  Parathyroid Hormone, Calcitonin, Calcium and Phosphate Metabolism, Vitamin D, Bone, and Teeth

Complete Chapter Questions And Answers
 

Sample Questions

1. A man consumes a high Ca2+ meal. Which of the following would be an appropriate compensatory response to the postprandial changes in plasma [Ca2+] concentration?
A. Increased calcitonin secretion
B. Increased formation of 1,25-(OH)2D3
C. Increased osteoclastic activity
D. Increased renal Ca2+ reabsorption
E. Increased osteocytic osteolysis

ANS: A

2. Which of the following is not a direct effect of PTH?
A. Increased renal Ca2+ reabsorption
B. Decreased renal phosphate reabsorption
C. Increased intestinal Ca2+ and phosphate absorption
D. Increased Ca2+ and phosphate resorption from bone
E. Increased renal production of 1,25-(OH)2D3

ANS: C

3. Which of the following would cause the most rapid increase in free ionized plasma Ca2+ concentration?
A. Increased osteocytic osteolysis
B. Increased osteoclastic activity
C. Increased formation of 1,25-(OH)2D3
D. Increased renal Ca2+ reabsorption
E. Increased intestinal Ca2+ absorption

ANS: A

Questions 4-6: Match each of the following patients in questions 4 and 6 with the following physiological changes.

Plasma [PTH] Plasma [1,25-(OH)2D3] Plasma [Phosphate]
A.
B.
C.
D.
E.

4. Most patients with rickets.

ANS: C

6. Most patients with osteomalacia.

ANS: C

7. A lethargic 60-year-old woman has complained of fatigue, depression, weakness, and constipation for several years. She has been taking several over-the-counter vitamin preparations for years. Abdominal x-rays reveal kidney stones and urine calcium is high. Her PTH level is low. Which of the following is the most likely cause of her symptoms?
A. Vitamin D excess
B. Primary hyperparathyroidism
C. Secondary hyperparathyroidism
D. Surgical hypoparathyroidism
E. Poor exposure to sunlight

ANS: A

8. Which of the following would not be a prominent response to PTH?
A. Increased Ca2+ reabsorption in the proximal tubule
B. Increased osteocytic osteolysis
C. Increased osteoclastic activity
D. Increased formation of 1,25-(OH)2D3 in the proximal tubule
E. Decreased phosphate reabsorption in the proximal tubule

ANS: A