Its cells are ovoid and arranged in clusters or arches (glomus is Latin for "ball").

[citation needed] In response to increased potassium levels, renin or decreased blood flow to the kidneys, cells of the zona glomerulosa produce and secrete the mineralocorticoid aldosterone into the blood as part of the renin–angiotensin system.

[1] Although sustained production of aldosterone requires persistent calcium entry through low-voltage activated Ca2+ channels, isolated zona glomerulosa cells are considered nonexcitable, with recorded membrane voltages that are too hyperpolarized to permit Ca2+ channels entry.

[2] However, mouse zona glomerulosa cells within adrenal slices spontaneously generate membrane potential oscillations of low periodicity; this innate electrical excitability of these cells provides a platform for the production of a recurrent Ca2+ channels signal that can be controlled by angiotensin II and extracellular potassium, the 2 major regulators of aldosterone production.

[5] Voltage-dependent calcium channels have been detected in the zona glomerulosa of the human adrenal, which suggests that calcium-channel blockers may directly influence the adrenocortical biosynthesis of aldosterone in vivo.