What evidence would support a hypothesis that the secretion of thyroid hormone is controlled by a negative feedback loop?

Question

Quizplus · Accepted Answer

In a negative feedback loop, an increase in the product (in this case, thyroid hormone) leads to a decrease in the production of the hormone's release-stimulating factor (TSH). Therefore, after taking thyroid hormone, a person's TSH levels should decrease if thyroid hormone secretion is controlled by a negative feedback loop. Choice A is incorrect because an increase in TSH levels would suggest that thyroid hormone levels are low and the body is trying to stimulate secretion. Choice C is incorrect because taking TSH would lead to an increase in thyroid hormone levels. Choice D is incorrect because thyrotropin-releasing hormone is the hormone that stimulates TSH production, not the other way around. Choice E is incorrect because there is no such thing as thyrotropin release-inhibiting hormone.

What Evidence Would Support a Hypothesis That the Secretion of Thyroid