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Adrenal Glands

A gland located on each kidney that secretes hormones regulating metabolism, sexual function, water balance, and stress.

PubMed Health Glossary
(Source: NIH - National Institute of Allergy and Infectious Diseases)

About the Adrenal Glands

The adrenal glands, located on the top of each kidney, are responsible for releasing different classes of hormones.

The outer part of the gland, called the adrenal cortex, produces the hormones cortisol (pronounced KAWR-tuh-sohl) and aldosterone (pronounced al-DOS-tuh-rohn). The inner part of the gland, called the adrenal medulla (pronounced muh-DUHL-uh), produces the hormones adrenaline and noradrenaline.

These hormones—cortisol, aldosterone, adrenaline, and noradrenaline—control many important functions in the body, including:

  • Maintaining metabolic processes, such as managing blood sugar levels and regulating inflammation
  • Regulating the balance of salt and water
  • Controlling the "fight or flight" response to stress
  • Maintaining pregnancy
  • Initiating and controlling sexual maturation during childhood and puberty

The adrenal glands are also an important source of sex steroids, such as estrogen and testosterone.
NIH - Eunice Kennedy Shriver National Institute of Child Health and Human Development

Terms to know

Adrenal Cortex
The outer part of the adrenal gland (a small organ on top of each kidney). The adrenal cortex makes androgen and corticosteroid hormones.
Adrenal Medulla
The inner part of the adrenal gland (a small organ on top of each kidney). The adrenal medulla makes chemicals such as epinephrine (adrenaline) and norepinephrine (noradrenaline) which are involved in sending nerve signals.
Hormones
A messenger molecule that helps coordinate the actions of various tissues; made in one part of the body and transported, via the bloodstream, to tissues and organs elsewhere in the body.
Kidney
One of a pair of organs in the abdomen. The kidneys remove waste and extra water from the blood (as urine) and help keep chemicals (such as sodium, potassium, and calcium) balanced in the body. The kidneys also make hormones that help control blood pressure and stimulate bone marrow to make red blood cells.
Metabolism
The chemical changes that take place in a cell or an organism. These changes make energy and the materials cells and organisms need to grow, reproduce, and stay healthy. Metabolism also helps get rid of toxic substances.

Terms to know

Adrenal Cortex
The outer part of the adrenal gland (a small organ on top of each kidney). The adrenal cortex makes androgen...
Adrenal Medulla
The inner part of the adrenal gland (a small organ on top of each kidney). The adrenal medulla makes chemical...
Hormones
A messenger molecule that helps coordinate the actions of various tissues; made in one part of the body and t...
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