part of part of blood vessel endothelial cell capillary endothelial cell 2010-08-24T10:15:00Z FMA:67756 BTO:0004956 CALOHA:TS-0112 An endothelial cell found in capillaries. https://cellxgene.cziscience.com/cellguide/CL_0002144 Capillary endothelial cells are particularly essential in the formation and function of capillaries - the smallest and most widespread blood vessels in the body. They play two primary roles: barrier function and transport function. Acting as barriers, they strictly control the passage of nutrients, gases, biological molecules, and cells between the blood and the surrounding tissues. This function not only provides a protective shield to internal organs against potentially harmful substances but also regulates the fluid and solute exchange. In terms of transport, these cells facilitate the diffusion of oxygen and essential nutrients from the bloodstream into the tissues. Concurrently, they allow waste products like carbon dioxide to pass from tissues into the bloodstream for removal, making these cells exceptionally instrumental in maintaining the body’s homeostasis. Moreover, capillary endothelial cells are also actively involved in numerous other physiological processes such as inflammation, blood clotting, and angiogenesis. During inflammation, they can specifically express and secrete molecules to attract white blood cells to sites of damage. Similarly, in blood clotting, they produce substances that prevent blood cells from sticking to the vessel wall and deter the formation of unnecessary clots. In angiogenesis, they proliferate and organize the formation of new blood vessels, crucial for wound healing and embryonic development. The disruption of their function contributes to pathological conditions like edema, thrombosis, and several cardiovascular diseases. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) squamous endothelial cell microvascular endothelial cell Homo sapiens endothelium of capillary