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Related to alpha receptor: beta receptor
a site on a cell that, upon interaction with epinephrine or norepinephrine, controls vasoconstriction, intestinal relaxation, pupil dilation, and other physiological processes. Compare beta-receptor.
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|Noun||1.||alpha receptor - 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)|
sympathetic nervous system - originates in the thoracic regions of the spinal cord; opposes physiological effects of the parasympathetic: reduces digestive secretions; speeds the heart; contracts blood vessels
receptor - a cellular structure that is postulated to exist in order to mediate between a chemical agent that acts on nervous tissue and the physiological response