Quick Facts
Vascular endothelium is the layer of epithelial cells that lines the lumina of blood vessels; it originates from the mesoderm (Dorland, 2011).
Related parts of the anatomy
Structure
The vascular endothelium is a key component of the tunica intima of the artery wall. It is the innermost layer of the artery surrounding the lumen, which separates the various cells and molecules within the blood from the surrounding tissue. The endothelium is therefore in direct contact with the bloodstream.
The endothelium is composed of a single layer of simple squamous endothelial cells. These cells form a continuous and uninterrupted sheet, or lining, around the lumen of the artery.
Anatomical Relations
The endothelium lies on the basement membrane of the blood vessel. This membrane affixes the endothelium to the connective tissue as well as providing the vessel wall with strength. The basement membrane is attached to the subendothelial connective tissue layer of the tunica intima.
Function
The vascular endothelium presides over the movement of cells in and out the blood as well as the exchange of molecules between the blood and surrounding tissues. The endothelium has also been seen to influence blood flow by acting as a mechanoreceptor when shear stress is applied to the vessel and transmitting the signal to intracellular organelles resulting in an alteration in vascular tone (Akira and Joji, 1993).
List of Clinical Correlates
- Atherosclerosis
- Thrombosis
References
Akira, K. and Joji, A. (1993) 'Vascular Endothelial Cell Functions and Biomechanics', Endothelium, 1(2), pp. 127-130.
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
