Which of the following statements regarding thyroid physiology are true?
A. Normally about 20% of T3 is secreted directly from the thyroid gland
B. The thyroid gland is the only endogenous source of T4
C. Excess thyroid hormone results in an increase in the number of ATP-dependent sodium pumps on the cell membrane
D. The majority of thyroid hormone in circulating plasma is bound to albumin, thus limiting the availability of the metabolically active form
Answer:A
Which of the following statements regarding thyroid physiology are true?
A. Normally about 20% of T3 is secreted directly from the thyroid gland B. The thyroid gland is the only endogenous source of T4 C. Excess thyroid hormone results in an increase in the number of ATP-dependent sodium pumps on the cell membrane D. The majority of thyroid hormone in circulating plasma is bound to albumin, thus limiting the availability of the metabolically active form