vascular smooth muscle vascular smooth muscle vascular smooth muscle is the type of smooth muscle that makes up most of the walls of blood vessels. vascular smooth musclediagram showing the location of vascular smooth muscle cells.vascular smooth muscle cells, isolated from human aorta, growing and forming a monolayer in cell culture.detailspart ofsmooth muscle wall of blood vessels.identifiersmeshd009131anatomical terminology structure vascular smooth muscle refers to the particular type of smooth muscle found within, and composing the majority of the wall of blood vessels. nerve supply vascular smooth muscle is innervated primarily by the sympathetic nervous system through adrenergic receptors (adrenoceptors). the three types present are: alpha-1, alpha-2 and beta-2 adrenergic receptors|. the main endogenous agonist of these cell receptors is norepinephrine (ne). the adrenergic receptors exert opposite physiologic effects in the vascular smooth muscle under activation: alpha-1 receptors. under ne binding alpha-1 receptors cause vasoconstriction (contraction of the vascular smooth muscle cells decreasing the diameter of the vessels). these receptors are activated in response to shock or low blood pressure as a defensive reaction trying to restore the normal blood pressure. antagonists of alpha-1 receptors (doxazosin, prazosin) cause vasodilation (a decrease in vascular smooth muscle tone with increase of vessel diameter and decrease of the blood pressure). (