Science Word Wednesday: Endothelium

Sep 16, 2020
By Madison Williams


(noun. /en-do-THEE-lee-uhm)

What does it mean?

The endothelium is a single layer of cells that makes up the inner layer of our blood vessels (arteries, veins, and capillaries). The cells in this layer are referred to as “endothelial cells.” These cells are important parts of the cardiovascular system–the system that includes the heart and blood vessels. They help control blood flow by tightening (constricting) or widening (dilating) blood vessels, and also help form blood clots to stop bleeding. The endothelial cells can also make and release proteins that act as signals to increase or decrease blood pressure. 

An illustration of the endothelium in an artery and vein.

How do I use it in a sentence?

“The patient’s endothelium was damaged by a viral infection.”

Fields of study in which this word is commonly used:

Vascular biology, cardiology

Edited by Emma Goldberg and Anna Wheless