Beta and Alpha receptors are illustrated. What occurs when they are stimulated and antagonized by medication?
In 1948, adrenergic receptors were subdivided into alpha and beta by Ahlquist (a graduate of the University of Washington). The distinction was based on sensitivities of different organs to catecholamines of closely related structure. Regulation of the functions of different organs depends to a greater or lesser extent on alpha or beta receptors. Pharmacological differentiation of alpha and beta receptors, and application of this technology to the treatment of disease, is an outstanding biomedical achievement.
Alpha receptors are located postsynaptically at sympathetic neuroeffector junctions of many organs. In general, alpha receptors mediate excitation or increased activity of the effector cells. Vascular smooth muscle is an important site of alpha receptors. SNS activity maintains vascular tone, and thus blood pressure, by maintaining a tone of neurotransmitter on vascular alpha receptors.
Beta receptors are also located postsynaptically at sympathetic neuroeffector junctions of many organs. In general, beta receptors mediate relaxation or decreased activity of the effector cells. Thus, blood vessels dilate and uterine smooth muscle relaxes in response to activation of beta receptors. Heart muscle is an important exception to this ...
Beta and Alpha receptors are explored.