The body's stress hormone response: When the brain perceives stress, the hypothalamus releases corticotropin-releasing factor (1), which triggers the release of adrenocorticotropin (ACTH) (2) from the pituitary gland. ACTH (2) travels through the bloodstream and (along with signals from the brain sent through the autonomic nervous system) stimulates the adrenal glands to release cortisol and epinephrine into the bloodstream (3). Cortisol and epinephrine (3) help provide energy, oxygen, and stimulation to the heart, the brain, and other muscles and organs (4) to support the body's response to stress. When the brain perceives that the stress has ended, it allows hormone levels to return to their baseline values.