[From adrenal, formed from ad- plus renal, ‘of the kidneys’, from Latin renes, kidney.]

The two adrenal glands lie on top of the kidneys. One part of each makes adrenaline and noradrenaline (in US epinephrine and norepinephrine), needed to prepare for stress and muscular activity. Adrenalectomy (Greek ektomē, excision) is surgical excision of all or part of the adrenal glands; the adjective adrenocortical refers to the outer portion of the adrenal glands, while adrenergic refers to or denotes nerve cells in which adrenaline, noradrenaline, or a similar substance acts as a neurotransmitter.