Definition

A thin layer of flat cells that forms the inner lining of blood vessels, lymph vessels, and certain body cavities.

Example

The endothelium plays a crucial role in regulating blood flow and maintaining vascular health.

Conversation

I just learned about the endothelium in my biology class.

Oh really? What is it exactly?

It's a layer of cells that lines blood vessels and other cavities in the body.

That sounds interesting! I didn't know it had such an important role.

Synonyms & Antonyms

Root Explanation

Endothelium → It is formed from "endo-" (from Greek "endon", meaning within) and "thelium" (from Greek "thēlē", meaning nipple or tissue). The word "endothelium" refers to the tissue that lines the interior surface of blood vessels and lymphatic vessels, thus being the tissue that is found within these structures.

Memory Tip

Think of 'within' ('endo-') and 'tissue' ('thelium') to remember that endothelium is the tissue that lines the inside of blood vessels.

Visually Confused Words