Vascular wall

The **vascular wall** is the multi-layered structure forming the outer boundary of blood vessels such as arteries, veins, and capillaries. It consists of three main layers: - The **tunica intima**, the innermost layer, is made up primarily of a single layer of endothelial cells and a supporting basement membrane[3][5][7]. - The **tunica media** is the middle layer, composed mostly of smooth muscle cells and elastic fibers, responsible for regulating vessel diameter and thus blood pressure and flow[1][3][5]. - The **tunica adventitia** (externa) is the outermost layer, containing connective tissue, fibroblasts, nerves (nervi vasorum), and small blood vessels (vasa vasorum) that supply the larger vessel[3][5][2]. Cells present include **endothelial cells**, **vascular smooth muscle cells**, fibroblasts, pericytes (in smaller vessels), and others[1][3][6]. The vascular wall is central to many physiological and pathological processes but is not itself a discrete molecular entity and thus is not classified as a canonical molecular target[1][3][5]. If your intention was to refer to a specific molecular component, cell type, or protein within the vascular wall (such as the endothelin receptor, vascular cell adhesion molecule 1, or smooth muscle actin), please specify, and a structured molecular target entry can be provided for that entity.