The adrenal glands are small pyramid-shaped organs located on top of the kidneys. They are responsible for secreting and storing hormones, including epineprhine (also called adrenaline), norepinephrine, and glucocorticoids. When the body experiences stress, the adrenal gland increases output of these hormones. When released into the body, epineprhine causes various physiological changes in the body (such as increased blood flow to the muscles and increased lung function) that are known as the "fight-or-flight" response: preparing the body to face a threat or run away from it. Corticosteroids (principally cortisol, in humans) also help the body to mobilize and replenish energy stores in times of danger or stress. However, long-term stress can cause the overaccumulation of corticosteroids, which can actually cause harm to the body and brain.