adrenergic receptor [L, ad + ren, kidney; Gk, ergon, work; L, recipere, to receive] , a site in a sympathetic effector cell that reacts to adrenergic stimulation. Two types of adrenergic receptors are recognized: alpha-adrenergic, which act in response to sympathomimetic stimuli, and beta-adrenergic, which block sympathomimetic activity. In general, stimulation of alpha receptors is excitatory of the function of the host organ or tissue, and stimulation of the beta receptors is inhibitory.
