Adrenal cortex. Light micrograph of a section through the cortex (outer region) of the adrenal gland. At upper left is the outer capsule (blue). Below this are seen two zones of the cortex. The upper zona glomerulosa (darker purple) contains secretory cells arranged in irregular rounded clumps. The cells produce the hormone aldosterone, which controls sodium and potassium levels in the body and helps to regulate blood pressure. The lower zona fasciculata (lighter) consists of narrow cords of secretory cells that make glucocorticoid hormones such as cortisol, which promote the release of glucose into the bloodstream. Magnification unknown.