
Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Zona glomerulosa
Introduction
The zona glomerulosa of the adrenal gland is the most superficial layer of the adrenal cortex, lying directly beneath the adrenal gland’s capsule. Its cells are ovoid in shape and are arranged in clusters or arches (glomus is Latin for “ball”).
In response to increased potassium levels or decreased blood flow to the kidneys, cells of the zona glomerulosa secrete the mineralocorticoid aldosterone into the blood as part of the renin-angiotensin system. Aldosterone regulates the body’s concentration of electrolytes, primarily sodium and potassium, by acting on the distal convoluted tubule of kidney nephrons to:
- increase sodium reabsorption
- increase potassium excretion
- increase water reabsorption through osmosis
The enzyme aldosterone synthase acts in this location.

External links
- Histology image: 14502loa – Histology Learning System at Boston University
- Template:AnatomyAtlasesMicroscopic – “Adrenal Gland”
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-632-7753
