What is the role of adrenocorticotropic hormone (ACTH)?

Adrenocorticotropic hormone (ACTH) plays a critical role in the endocrine system by stimulating the adrenal cortex to produce and secrete glucocorticoids, particularly cortisol. This hormone is essential for stress response, as glucocorticoids help regulate various bodily functions such as metabolism, immune response, and the body's overall reaction to stress.

When ACTH is released from the anterior pituitary gland in response to corticotropin-releasing hormone (CRH) produced by the hypothalamus, it acts on the adrenal cortex, signaling it to increase the secretion of glucocorticoids. This process is a key component of the hypothalamic-pituitary-adrenal (HPA) axis, which is crucial for maintaining homeostasis in the body.

The other options describe functions that are not directly related to the role of ACTH. For instance, insulin release is primarily stimulated by glucose levels in the bloodstream and is related to the pancreas rather than the adrenal cortex. Metabolism is a broad function regulated by various hormones, including thyroid hormones and insulin, but ACTH specifically influences glucocorticoids rather than directly regulating metabolic processes. Lastly, while factors like stress hormones may affect heart rate indirectly, ACTH does not