Aclient undergoing an evaluation of hormone levels asks, "what regulates the hormone levels? "

A client undergoing an evaluation of their hormone levels asks "What regulates the hormone levels?" Which response by the nurse would be considered most accurate?

a) The hypothalamic-pituitary-target cell system

b) Exogenous forms of hormones  

c) The positive feedback loop

d) The hypophysial portal system

a) The hypothalamic-pituitary-target cell system

Explanation:

Hormone release in the body system are principally regulated via a negative feedback system. In the negative feedback system, a stimuli evoke the production of an hormone (for example lets say production of thyroid hormone from the signaling produced by anterior pituitary glands); now, once this hormone gets to a substantial certain level, a negative feedback is generated to the hypothalamic-pituitary-target cell system  and anterior pituitary to inhibit further signaling of hormonal production to the thyroid gland. This process thereby regulates the production of hormone levels.

the answer is definitely a