Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?
A) greater production of T3 than of T4
B) hyposecretion of TSH
C) hypersecretion of MSH
D) a decrease in the thyroid secretion of calcitonin

Question

Quizplus · Accepted Answer

Hypothyroidism, characterized by insufficient levels of thyroid hormones, is most directly caused by hyposecretion of Thyroid Stimulating Hormone (TSH) from the pituitary gland when iodine levels are normal. TSH stimulates the thyroid gland to produce thyroid hormones (T3 and T4), so less TSH means less stimulation and thus lower hormone production.

Which of the Following Is the Most Likely Explanation for Hypothyroidism