ACTH stimulates which part of the body to release cortisol?

ACTH, or adrenocorticotropic hormone, is a hormone produced by the anterior pituitary gland. Its primary role is to stimulate the adrenal cortex, which is the outer layer of the adrenal glands located on top of the kidneys. In response to ACTH, the adrenal cortex releases cortisol, a steroid hormone that plays a critical role in regulating metabolism, immune response, and stress response.

Cortisol is often referred to as the "stress hormone" because its levels increase in response to stress, and it helps the body manage stress by increasing glucose availability and modulating inflammation. The link between ACTH and the adrenal cortex is a key part of the hypothalamic-pituitary-adrenal (HPA) axis, a critical regulatory system in the body.

In contrast, while the pancreas, thyroid gland, and kidneys play vital roles in other physiological processes, they are not directly stimulated by ACTH to release cortisol. The pancreas primarily regulates blood sugar levels through insulin and glucagon, the thyroid gland regulates metabolism through thyroid hormones, and the kidneys are involved in fluid balance and waste excretion. Therefore, the adrenal cortex is the correct answer as it is the site of cortisol production following stimulation by ACTH.