The Main Negative Feedback on TSH Secretion is Provided By

Question

The main negative feedback on TSH secretion is provided by
A) TRH
B) Body temperature
C) T4 and T3 levels in the blood
D) Sex steroids
E) TBG from the liver

Accepted Answer

T4 (thyroxine) and T3 (triiodothyronine) levels in the blood provide the main negative feedback on TSH (Thyroid Stimulating Hormone) secretion. When T3 and T4 levels are high, they signal the pituitary gland to reduce TSH production, thereby decreasing thyroid hormone production.