What it isThe endothelial glycocalyx is a soft, gel-like coating of sugars and sugar-linked proteins that lines the inside of every blood vessel. It sits between flowing blood and the endothelial cells that form the vessel wall, forming a protective, slippery layer that is normally invisible on a standard blood test.
Evidence statusCited entry Model roleShows the intermingled surface layer as one system rather than a stack of separate coatings.