Zona Fasciculata Cells (Cortisol Makers)

Cells in long columns

Your two adrenal glands sit on top of your kidneys. Their outer part has three layers. The zona fasciculata (say fuh-sik-yoo-LAH-tuh) is the middle layer, and it is the thickest one.

Its cells line up in long, straight columns, with tiny blood tubes running between them. "Fascicle" means "bundle", because the columns look like bundles of sticks.

The cells are full of little drops of fat. These drops hold cholesterol, the building block the cells use to make their hormone. All those drops make the cells look pale and foamy.

Cortisol for busy days

These cells make a hormone called cortisol (say KOR-tih-sol). It does several helpful things:

• It keeps enough sugar in your blood between meals, so your brain and muscles have energy.
• It helps your body handle stress, like a big test or being sick.
• It helps calm down swelling.

Your body makes the most cortisol in the morning, which helps you wake up and get going. A message called ACTH, from the pituitary gland, tells these cells when to make more.

Zona fasciculata quiz