alpha-adrenoceptor
n 1: receptors postulated to exist on nerve cell membranes of
the sympathetic nervous system in order to explain the
specificity of certain agents that affect only some
sympathetic activities (such as vasoconstriction and
relaxation of intestinal muscles and contraction of smooth
muscles) [syn: {alpha receptor}, {alpha-adrenergic
receptor}, {alpha-adrenoceptor}]