The cells lining the blood vessels belong to the category of

The cells lining the blood vessels belong to the category of endothelial cells. These cells form the endothelium, which is a thin layer of simple squamous cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. These cells have unique functions in vascular biology, including blood clotting, blood vessel tone, hemostasis, and regulating inflammation.