A pair of glands in the endocrine system located just above each kidney. This glands is composed of two sections, the cortex and the medulla, that function independently of each other. The cortex secretes steroids, such as aldosterone, cortisol, androgens, estrogens, and progestins. The medulla secretes epinephrine and norepinephrine. The adrenal glands are regulated by adrenocorticotropic hormone, which is secreted by the pituitary gland.