The diagram below illustrates feedback control as exerted by

Last updated: 1/27/2023

The diagram below illustrates feedback control as exerted by the hormone thyroxine Following surgical removal of the thyroid gland the level of TSH in the blood will increase inhibition Thyroxine feedback loop A B Which of the following best explains this increase C hypothalamus thyrotropin releasing hormone TRH D anterior pituitary thyroid stimulating hormone TSH inhibition thyroid gland thyroxine A decrease in thyroxine levels means a loss of inhibition to the hypothalamus and ante rior pituitary leading to increased TSH secretion Thyroxine will remain bound to thyroxine receptors on various body cells and these body cells secrete additional hormones that stimulate the anterior pituitary to se crete TSH Residual blood thyroxine prior to thyroid gland removal will bind to cells in the anterior pituitary signaling more TSH secretion Thyroxine that was stored in the anterior pituitary prior to thyroid gland removal will sig nal more TSH secretion