What is the key hormone that plays a role in the stress response and is secreted by the adrenal cortex?

Cortisol is a critical hormone that plays a significant role in the body’s stress response and is secreted by the adrenal cortex. Its primary function is to mobilize energy by increasing blood glucose levels, enhancing the metabolism of fats, proteins, and carbohydrates. This action helps the body to respond effectively to stressors, whether they are physical, emotional, or environmental.

In times of stress, the hypothalamus signals the release of adrenocorticotropic hormone (ACTH) from the pituitary gland, which in turn stimulates the adrenal cortex to produce and release cortisol. Elevated cortisol levels provide the necessary resources for the body to manage stress, including increasing cardiovascular function and modulating immune responses.

While adrenaline and noradrenaline, secreted by the adrenal medulla, are also involved in the stress response, they serve different purposes, primarily facilitating immediate fight-or-flight responses. Aldosterone, another hormone produced by the adrenal cortex, is primarily involved in regulating blood pressure and electrolyte balance rather than in the direct stress response.

The understanding of cortisol's role in the stress response underscores its importance in both physiological and psychological processes and establishes it as the key hormone in this context.