Question

By themselves, two hormones ADH and CRH each cause a small increase on ACTH secretion. During stress the brain signals release of CRH, which travels from the hypothalamus to the anterior pituitary where it causes a larger ACTH release than when only ADH or itself are present. Which is a good descriptor of CRH?

A) synergism with ADH
B) enhances parasympathetic nervous system
C) antagonist with ADH
D) positively modulated by ACTH

Answer 1

CRH plays a pivotal role in the body's stress response by signaling the anterior pituitary to release ACTH, and it works synergistically with ADH to increase this secretion. CRH is not an enhancer of the parasympathetic nervous system or an antagonist of ADH, nor is it modulated by ACTH.

Step-by-step explanation:

The corticotropin-releasing hormone (CRH) plays a crucial role in the body's response to stress, functioning as the primary hypothalamic factor that stimulates the anterior pituitary gland to release adrenocorticotropic hormone (ACTH). When CRH and antidiuretic hormone (ADH) interact, they have a synergistic effect on ACTH secretion, meaning that their combined action is greater than the sum of their individual effects. Thus, CRH can be described as having synergism with ADH, making it a crucial modulator of the hypothalamic-pituitary-adrenal (HPA) axis during stress situations. It does not enhance the parasympathetic nervous system nor does it function as an antagonist of ADH. Also, ACTH does not modulate CRH positively; rather, it's the other way round where CRH regulates the secretion of ACTH.