Adrenal gland. Light micrograph of a longitudinal section through an adrenal gland. Beneath the capsule at top (blue), the gland is divided into an outer cortex and an inner medulla. Three layers of hormone secreting cells make up the cortex. Directly beneath the capsule, the zona glomerulosa (dense pink dots) contains cells that secrete aldosterone. The zona fasciculata directly beneath (dispersed pink dots) contains cortisol-secreting cells. The zona reticularis (dense pink dots) below is thought to secrete sex hormones. The innermost layer is the adrenal medulla (bottom, blue) which secretes adrenaline (epinephrine) and noradrenaline (norepinephrine).