En·do·the·li·um n.; pl. Endothelia Anat. The thin epithelium lining the blood vessels, lymphatics, and serous cavities. See Epithelium.
◄ ►
endothelium
n : an epithelium of mesoblastic origin; a thin layer of
flattened cells that lines the inside of some body
cavities
[also: endothelia (pl)]