13.9 The Adrenal Glands

adrenal glands

• which are also known as the suprarenals, are so named because they are located on top of each kidney

• each of these glands consists of an outer portion, known as the adrenal cortex, and the middle portion, which is the adrenal medulla

electrolytes

are mineral substances—>calcium, chloride, magnesium, phosphorus, sodium, and potassium—that are normally found in the blood and other bodily fluids

androgens

sex hormones secreted by the gonads, the adrenal cortex, and fat cells

corticosteroids

• the steroid hormones produced by the adrenal cortex

• the same term describes synthetically produced equivalents that are administered as medications

aldosterone

a corticosteroid that regulates the sodium and water levels in the body by increasing sodium reabsorption and potassium excretion by the kidneys

cortisol

• also known as hydrocortisone, is a corticosteroid that has an anti-inflammatory action

• it also helps regulate the metabolism of carbohydrates, fats, and proteins in the body

epinephrine

• also known as adrenaline, stimulates the sympathetic nervous system in response to physical injury or to mental stress such as fear

• it makes the heart beat faster and can raise blood pressure

• it also helps the liver release glucose and limits the release of insulin

norepinephrine

• both a hormone and a neurohormone

• it is released as a hormone by the adrenal medulla and as a neurohormone by the sympathetic nervous system

• it plays an important role in the “fight-or-flight response” by raising blood pressure, strengthening the heartbeat, and stimulating muscle contractions