<Tr> <Th> FMA </Th> <Td> 63183 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The blood vessels are the part of the circulatory system, and microcirculation, that transports blood throughout the human body . There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart . The word vascular, meaning relating to the blood vessels, is derived from the Latin vas, meaning vessel . A few structures (such as cartilage and the lens of the eye) do not contain blood vessels and are labeled . </P> <P> The arteries and veins have three layers . The middle layer is thicker in the arteries than it is in the veins: </P>

What are the 4 types of blood vessels