Venules are small veins that serve as a link between larger veins and capillaries. These blood vessels therefore join veins at one end and capillaries at the other.
It can be said that the venules are small veins in charge of collecting the blood from the capillaries and taking it to the common veins. In this way, the venules play a very important role in the return of blood to the heart. It is important to remember at this point that blood is a liquid made up of plasma and different types of cells in suspension (platelets, red blood cells, white blood cells). Nutrients and oxygen are distributed throughout the body through the blood, and waste substances are collected.
As for the structure of the venules, it is similar to that of the veins. Venules have an internal layer (endothelium) and an adventitious or external layer (fibrous connective tissue), although they lack the elastic tissue that, in veins, is located between both sectors. It is important to mention that the venules, veins and venous capillaries constitute what is known as the venous system. Its function is to transport already deoxygenated blood that transports waste and carbon dioxide, making a route parallel to that of the arterial system, although in the opposite direction. In short, venules are a kind of blood vessel. Among the vessels we also find veins, capillaries, arterioles and arteries. In the specific case of the venules, through them the return of blood to the heart begins after passing through the capillaries.
