Hypothalamic–pituitary–adrenal axis

The hypothalamic–pituitary–adrenal axis (HPA axis) is a neuroendocrine axis that controls the secretion of corticosteroid stress hormones. The HPA axis has three components: the hypothalamus (a part of the brain located below the thalamus), the pituitary gland (a pea-shaped structure located below the hypothalamus), and the adrenal (also called "suprarenal") glands (small, conical organs on top of the kidneys).

Source: Wikipedia — Hypothalamic–pituitary–adrenal axis (CC BY-SA 4.0)