What is the Vascular Endothelium?

The term vascular endothelium refers to a single layer of cells lining the components of the entire cardiovascular system. This includes the heart and the three types of blood vessels: arteries, capillaries and veins. The vascular endothelium is part of an essential function of the body's circulatory system.

In general, the term "endothelium" is sufficient to describe the layer of cells that cover the interior walls of blood vessels. This feature, however, is usually given the "vascular" prefix to differentiate the layers of the heart and blood vessels from the endothelium of other areas of the body, such as the brain and eyes. The vascular endothelium in particular makes sure that the blood flows smoothly within the space of the blood vessel, which is known as lumen. The presence of vascular endothelium permits blood to travel farther, as well as transmits the white blood cells in it.

The endothelium of the vascular system is formed during a process called angiogenesis. During this process, the endothelial layers of cells are created with the collaboration of the blood vessels’ smooth walls with connective tissue cells called pericytes. These are also called mural cells due to their location at the vessels’ walls.

The vascular endothelium works alongside the lymphatic endothelium. This layer of cells lines the inner walls of the lymphatic capillaries, which get rid of excessive tissue fluid. The flow of this fluid, specifically called lymph while in the vessel and generally known as interstitial fluid, is controlled in the same way that the blood is by the vascular endothelium. The lymphatic capillaries are also components of the lymphatic system.

Both the vascular and lymphatic system comprise the circulatory system. This network of organs circulates blood, tissue fluid, nutrients and other substances between certain organs to maintain the body’s overall health. The vascular endothelium in particular is part of the vascular system, which consists of the heart and blood vessels that it lines.

The lack of the vascular endothelium can adversely affect the vascular system. For instance, tissue swelling could occur as a result of unregulated or increased rate of blood flow. Also, when the endothelium gets additional layers, which are made of plaque, the walls consequently thicken and restrict blood flow. This condition is known as atherosclerosis. A weakening or destruction of the endothelium in the heart and blood vessels can lead to cardiovascular problems such as heart disease or heart attack.