The Cardiovascular system consists of the heart and blood vessels, and overlaps with the circulatory system and the lymphatic system.
The main function of the heart is to pump blood into the major vessels so that it can be distributed throughout the body.
There are many types of blood vessels—aorta, arteries, arterioles, capillaries, venules, veins, venae cavae—and each have a specific function. To learn about each one, check out the circulatory system.