The mineralocorticoids are deoxycorticosterone and aldosterone. Sinusoids arise from multiple arterioles in the capsule. Course between cell cords. Cells are regularly arranged in parallel cords, one to two cells thick. Component cells are cuboidal, frequently containing two vesicular nuclei.
Vacuoles seen in some cells represent dissolved lipid droplets.
Cholesterol is chiefly present in this zone. Cell cords are surrounded by sinusoids. Secretes the glucocorticoids, cortisone and cortisol. Innermost layer of the adrenal cortex. Cells are arranged in irregular cords, are smaller than those of the zona fasciculata, and stain darker.