endóthel

Endothelium refers to the single layer of cells that lines the interior surface of blood vessels and lymphatic vessels. This lining, known as the endothelium, is a type of simple squamous epithelium. It is critical for maintaining vascular homeostasis, playing a role in processes such as blood clotting, regulating blood pressure, and controlling the passage of substances into and out of the bloodstream. The endothelium is not merely a passive barrier; it is a metabolically active tissue.

The endothelial cells secrete various substances, including vasodilators like nitric oxide and vasoconstrictors like endothelin. They also participate in inflammation by expressing adhesion molecules that attract white blood cells. Furthermore, the endothelium is involved in angiogenesis, the formation of new blood vessels, and in the regulation of immune cell trafficking. Diseases affecting the endothelium, often termed endothelial dysfunction, are implicated in a wide range of cardiovascular conditions, including atherosclerosis, hypertension, and diabetes. Maintaining healthy endothelial function is therefore a key aspect of cardiovascular health.