#february2020usmle2ck
Which of the following controls the secretion of thyrotropin?
A- Concentration of iodine in the thyroid gland
B- Concentration of thyroid hormones in the blood
C- Concentration of thyroid hormones in the thyroid gland
D- Concentration of thyrotropin in the pituitary gland
Which of the following controls the secretion of thyrotropin?
A- Concentration of iodine in the thyroid gland
B- Concentration of thyroid hormones in the blood
C- Concentration of thyroid hormones in the thyroid gland
D- Concentration of thyrotropin in the pituitary gland