| a site on a cell, as of the heart, that, upon interaction with epinephrine or norepinephrine, controls heartbeat and heart contractability, vasodilation, smooth muscle inhibition, and other physiological processes. |
| beta receptor | |
noun | |
| 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 vasodilation and increased heart beat) |