Adrenal cortical cell

Adrenal cortical cells, the ones in the outer layer of the adrenal gland, aren't piled up at random. They arrange themselves into cords, rows of cells lined up one behind another, and those cords sit inside an extensive capillary network: capillaries are the finest blood vessels, and there are a great many of them here. Picture a string of beads running between thin hoses on every side.

That cortex isn't uniform: it has distinct zones, and the cells in each zone make different classes of steroid hormones, a type of hormone built on the same basic chemical structure. Living in one zone or another is what decides which class of hormone a given cell builds.