Lumen of blood vessel

The **lumen of a blood vessel** is the hollow passageway inside a blood vessel (artery, vein, or capillary) through which blood flows[1][2][8]. The lumen is lined by a single layer of **endothelial cells** forming the endothelium[5][7]. Its diameter and shape vary depending on vessel type: arteries have smaller, rounder lumens and thicker walls to maintain pressure, while veins have larger, more irregular lumens to accommodate higher blood volume at lower pressure[1][4][6]. The lumenal space plays a passive role in health and disease: it allows flow, and narrowing by atherosclerosis or blockage by a clot leads to disease, but the lumen itself is not a molecular drug target or biologically active structure[8]. No drugs or therapies bind to or act on the lumen directly; pharmacologic effects on lumen size (such as with vasodilators) are mediated through smooth muscle receptors or endothelial factors in the vessel wall, not by targeting the lumen itself.

Other names

blood vessel lumenvessel lumenvascular lumenlumen of arterylumen of vein