Thyroid Physiology — Endocrine & Metabolic Physiology

Thyroid Physiology MCQs: practice questions

Sample Thyroid Physiology multiple-choice questions from Endocrine & Metabolic Physiology.

1. Thyroid Physiology 30 questions • Five related options • One best answer • Explanation 1. Thyroid follicular cells synthesize thyroid hormone using:

   • A. Iodide and thyroglobulin
   • B. Cholesterol and LDL
   • C. Tyrosine only without iodine
   • D. Calcium and phosphate
   • E. Acetylcholine and dopamine

2. Release of T3 and T4 requires:

   • A. Secretion of TSH from thyroid follicles
   • B. Direct diffusion of thyroglobulin into blood
   • C. TSH-independent exocytosis of free T4 from vesicles
   • D. Conversion of cholesterol to T4
   • E. Endocytosis of iodinated thyroglobulin and lysosomal digestion

3. The thyroid gland stores iodinated thyroglobulin primarily in the:

   • A. Follicular lumen
   • B. Nucleus
   • C. Blood plasma
   • D. Parathyroid cells
   • E. Adrenal medulla

4. Reverse T3 is:

   • A. A thyroid receptor agonist with higher activity
   • B. More potent than T3
   • C. Identical to T3
   • D. The major active thyroid hormone
   • E. Biologically inactive

5. Coupling of MIT and DIT produces:

   • A. T4
   • B. T3
   • C. TSH
   • D. TRH
   • E. rT3

6. During pregnancy, increased TBG causes:

7. Thyroid hormone is essential for normal:

8. Iodine deficiency can produce goiter because:

9. Peripheral conversion of T4 to T3 is mediated by:

10. Thyroid peroxidase is required for:

11. Graves disease results from antibodies that:

12. Iodide enters thyroid follicular cells from blood through the:

13. A patient with primary hypothyroidism is expected to have:

14. A child with severe untreated congenital hypothyroidism is at risk for:

15. T3 and T4 normally inhibit secretion of:

16. Hypothyroidism is expected to cause:

17. Hyperthyroidism is expected to cause:

18. Thyroid hormone promotes normal growth partly by acting synergistically with:

19. Thyroid hormone increases metabolic rate partly by increasing:

20. Methimazole primarily inhibits:

21. In Graves disease, TSH levels are usually:

22. A chronic elevation of TSH causes:

23. Propylthiouracil inhibits thyroid hormone synthesis by inhibiting:

24. TSH stimulates thyroid follicular cells through:

25. T3 is more biologically active than T4 by approximately:

26. Coupling of two DIT residues produces:

27. Most circulating T3 and T4 is bound to:

28. Organification refers to:

29. In hepatic failure, decreased TBG tends to cause:

30. TRH is secreted by the: