Stress and Your Body
Hypothalamic-Pituitary-Adrenal (HPA) Axis
Best known for its role in our body’s natural reaction to stress, the HPA Axis includes a group of hormone secreting glands from the nervous and endocrine systems. The primary function of the HPA Axis is to regulate the stress response. Below is a description of what occurs in one’s brain and body when experiencing something stressful:
When we are experiencing something stressful, the hypothalamus releases a hormone called corticotropin-releasing hormone (CRH).
CRH signals the pituitary gland to secrete a hormone called andrenocorticotropic hormone (ACTH) into the bloodstream.
ACTH travels down to the adrenal glands where it prompts the release of different hormones from different parts of the adrenal glands. It causes the secretion of a class of steroid hormones called glucocorticoids from the cortex – one of these glucocorticoids is cortisol, which plays an important role in the stress response. ACTH also triggers the secretion of epinephrine and norepinephrine from the adrenal medulla (center of the adrenal glands) – when released from the adrenal glands, they act as hormones.