The adrenal glands curve over the top of each |kidney| in the abdomen. Although it appears to be one organ, it is actually two small |glands|, each weighing about 1/4 ounce (7 grams). The adrenal |medulla| (inner part or zona glomerulosa) is an agent of the sympathetic nervous system and is activated by ~nerve~ impulses. The adrenal |cortex| (the outer part, or zona fasciculata) is a true endocrine gland activated by adrenocorticotrophic ~hormone~ (ACTH) sent out from the |pituitary gland|. The adrenal |medulla| secretes the catecholamines epinephrine and norepinepherine. These ~hormones~ help the body reduce stress. When the sympathetic nervous system reacts to intense emotions, such as fright or anger, large amounts of the ~hormone~ are released. This may cause a "fight or flight" reaction, in which ~blood~ pressure rises, the |pupils| widen, and ~blood~ is shunted to the most vital organs and to the skeletal muscles. The |heart| is also stimulated. The adrenal |cortex| secretes two ~hormones~: cortisol and aldosterone. These ~hormones~ are known collectively as corticosteroids. They help the body reduce stress and are essential for life. Cortisol is an energy generator. It regulates conversion of |carbohydrates| into glucose and directs reserves to the |liver|. It also supresses inflamation. Aldosterone regulates the mineral and water balance of the body. It prevents excessive loss of water through the |kidneys| and maintains the balance between sodium and potasium in the ~blood~ stream. This balance is important to the contractility of muscles.
