Circulatory system
So blood moves: heart→artery→arteriole→capillary→venule→vein→heart. This is called circulation. There are two different circulations in the circulatory system. The systemic circulation is how blood goes to most of the body. The pulmonary circulation is how blood goes through the lungs. (Pulmonary means ¨about the lungs¨). This is how it works in mammals, including humans. Circulatory systems of other vertebrates differ somewhat.