Thyroid-stimulating hormone (TSH) is released to stimulate thyroid hormone (TH) and is inhibited when plasma levels of TH are adequate. What is this an example of?
A)Positive feedback
B)Negative feedback
C)Neural regulation
D)Physiologic regulation

Question

Quizplus · Accepted Answer

Feedback systems provide precise monitoring and control of the cellular environment. Negative feedback occurs because the changing chemical, neural, or endocrine response to a stimulus negates the initiating change that triggered the release of the hormone. Thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates TSH secretion from the anterior pituitary. Secretion of TSH stimulates the synthesis and secretion of THs. Increasing levels of T₄ and triiodothyronine (T₃) then generate negative feedback on the pituitary and hypothalamus to inhibit TRH and TSH synthesis. A positive feedback loop would have the opposite effect. Neural regulation is a type of hormonal control that involves the nervous system. Physiologic is not a specific type of hormone regulation.

Thyroid-Stimulating Hormone (TSH) Is Released to Stimulate Thyroid Hormone (TH)