Question

The hormone thyroxine is released in response to a pituitary hormone called TSH. As thyroxine levels increase in the blood, they exert negative feedback on the release of TSH by the pituitary gland. What effect will this have on the release of TSH?

Answer 1

Negative effect on TSH release

Step-by-step explanation:

Thyroxine hormone is secreted by Thyroid gland into the bloodstream. In its active form of triiodothyronine it plays an important part in metabolism, growth, brain development etc.

Release of thyroxine hormone is a part of hypothalamic-pituitary-thyroid axis and follows negative feedback. When the levels of thyroxine increases in the blood, it inhibits the release of TRH( Thyroid-releasing hormone) from hypothalamus which in turn inhibits the release of TSH ( Thyroid-stimulating hormone) from anterior pituitary. Decreased TSH inhibits the secretion of Thyroxine from thyroid gland.