Zona reticularis

The innermost layer of the adrenal cortex, the zona reticularis sits beneath the zona fasciculata and atop the adrenal medulla.

Its cells are arranged in a network of cords (a reticulum) and have the same functions as cells of the zona fasciculata.

It is thought that the zona reticularis is the principal source of glucocorticoids and adrenal androgens, with the zona fasciculata activating only after prolonged stimulation.