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Overview of Adrenal Function


Ashley B. Grossman

, MD, University of Oxford; Fellow, Green-Templeton College

Last full review/revision Sep 2020| Content last modified Sep 2020
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Topic Resources
  • Cortex

  • Medulla

The adrenal cortex and adrenal medulla each have separate endocrine functions.

Adrenal glands

Adrenal glands

Adrenal cortex

The adrenal cortex produces

  • Glucocorticoids (primarily cortisol)

  • Mineralocorticoids (primarily aldosterone)

  • Androgens (primarily dehydroepiandrosterone and androstenedione)

Glucocorticoids promote and inhibit gene transcription in many cells and organ systems. Prominent effects include anti-inflammatory actions and increased hepatic gluconeogenesis.

Mineralocorticoids regulate electrolyte transport across epithelial surfaces, particularly renal conservation of sodium in exchange for potassium.

Adrenal androgens’ chief physiologic activity occurs after conversion to testosterone and dihydrotestosterone.

Adrenal medulla

The adrenal medulla is composed of chromaffin cells, which synthesize and secrete catecholamines (mainly epinephrine and lesser amounts of norepinephrine). Chromaffin cells also produce bioactive amines and peptides (eg, histamine, serotonin, chromogranins, neuropeptide hormones). Epinephrine and norepinephrine, the major effector amines of the sympathetic nervous system, are responsible for the “flight or fight” response (ie, chronotropic and inotropic effects on the heart; bronchodilation; peripheral and splanchnic vasoconstriction with skeletal muscular vasodilation; metabolic effects including glycogenolysis, lipolysis, and renin release).

Clinical syndromes

Most adrenal deficiency syndromes affect output of all adrenocortical hormones. Hypofunction may be primary (malfunction of the adrenal gland itself, as in Addison disease Addison Disease Addison disease is an insidious, usually progressive hypofunctioning of the adrenal cortex. It causes various symptoms, including hypotension and hyperpigmentation, and can lead to adrenal crisis... read more Addison Disease ) or secondary (due to lack of adrenal stimulation by the pituitary or hypothalamus, although some experts refer to hypothalamic malfunction as tertiary).

Adrenal hyperfunction causes distinct clinical syndromes depending on the hormone involved:

These syndromes frequently have overlapping features.

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