Which part of the adrenal gland is responsible for the regulation of stress response?

The adrenal gland has two main parts: the adrenal medulla and the adrenal cortex, which each play distinct roles in the body's response to stress. The adrenal cortex is responsible for producing corticosteroid hormones, such as cortisol, which are crucial for regulating various bodily functions during stress. When the body perceives a stressor, the hypothalamus signals the adrenal cortex to release cortisol and other glucocorticoids, helping to modulate metabolism, immune response, and maintain homeostasis.

In contrast, while the adrenal medulla also contributes to the stress response by releasing catecholamines (like adrenaline), its primary function is more aligned with the immediate "fight or flight" response rather than long-term stress regulation. The pineal gland and the hypothalamus, although important in hormonal regulation and other functions, are not the primary sites for the regulation of the stress response associated with the adrenal gland. Thus, the adrenal cortex is definitively the key player in the regulation of the body's adaptive processes during stress.