|Endothelial cells, which form the tunica intima, encircle an erythrocyte (E).|
Endothelium is a layer of cells that line the walls of the circulatory system which carries blood around the body. The cells form a membrane so that certain substances, such as nutrients, can move through the walls. In an adult human there is about 1 kg of endothelium, which would cover an area of about 7 m2. The endothelium plays an important part in controlling the flow of blood around the body.
- Cines, Douglas B. (2012). "Endothelial Cells in Physiology and in the Pathophysiology of Vascular Disorders". bloodjournal.hematologylibrary.org. http://bloodjournal.hematologylibrary.org/content/91/10/3527.full. Retrieved 25 October 2012.