Angiology is the scientific study of the vascular system, which includes arteries, veins, capillaries, and lymphatic vessels. The pump that makes it work, the heart, is also the object of its study. From a morphological and functional point of view, it is usually classified into blood vascular system (systema sanguineum), or the circulatory system, and the lymphatic system, which drains the body tissues.
The blood vascular system is composed in turn of three types of vessels: arteries, veins, and capillaries. Arteries carry oxygenated blood from the heart to the body, and vein deoxygenated (oxygen-poor) blood from the body back to the heart. Thus, they are responsible for keeping keep our tissues and organs alive. They are arranged in a closed-circuit manner, with the capillaries being the bridge or junction point between arteries and veins. Meanwhile, the lymphatic vessels do not carry blood but lympha, which is the excess fluid that builds up in the tissues.
Angiology also studies the structure of blood vessels and the vascular diseases that affect them. From the size of their lumen point of view, there are two types of arteries and veins. Therefore, a very small artery is called arteriole, while a very small-caliber vein is called venules. Both of them have smooth muscle constituting their middle layer, while the capillaries are made up only of squamous endothelial cells. Many inflammatory conditions damage these structures and can provoke a collapse of the inner walls and their occlusion.
Angiology also study the anatomical location of every blood vessel.
