The tissue which forms a single layer of cells lining various organs and cavities of the body, especially the blood vessels, heart, and lymphatic vessels. It is formed from the embryonic mesoderm.Compare with epithelium‘Laughter appears to cause the tissue that forms the inner lining of blood vessels, the endothelium, to dilate or expand in order to increase blood flow.’
- ‘This endothelium helps give vessels the elasticity needed to regulate blood pressure.’
- ‘The endothelium is a layer of cells that line the undersurface of the cornea and are essential to keeping the cornea clear.’
- ‘Blood vessels only work when both endothelia and vascular smooth muscle are bound together.’
- ‘The pulmonary endothelium represents a very large surface area, the major part of which lies in close contact with the alveoli.’
Late 19th century modern Latin, from endo-‘within’ + Greek thēlē ‘nipple’.