Endothelium

Endothelium is a layer of cells that line the walls of the circulatory system which carries blood around the body.^[1] 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 cells, which would cover an area of about 7m².^[1] The endothelium plays an important part in controlling the flow of blood around the body.

Endothelium
Diagram showing the location of endothelial cells
Transmission electron micrograph of a microvessel showing endothelial cells, which encircle an erythrocyte (E), forming the innermost layer of the vessel, the tunica intima.
Details
System	Circulatory system
Location	Lining of the inner surface of blood vessels and lymphatic vessels
Identifiers
MeSH	D004727
TH	H2.00.02.0.02003
FMA	63916
Anatomical terms of microanatomy [edit on Wikidata]