Adrenal gland. Light micrograph of a section through a healthy human adrenal gland. This is the medulla (inner layer), which is composed of closely packed clumps of secretory cells (light purple). Many venous channels drain blood through the medulla towards the medullary vein. The cells seen, have large, granular nuclei and strongly basophilic (easily stained) cytoplasm. The adrenal medulla secretes the hormones adrenaline and noradrenaline. But, unlike other endocrine glands, the adrenal gland's hormones are not secreted continuously, but stored and released only in response to nervous stimulation. Magnification unknown.