All the body parts of the circulatory system have different shapes, jobs, and purposes. Like the hearts job is to pump blood all around the body, the lungs is to give oxygen to the blood and give you fresh air. The livers is to clean the blood and send it to the heart. The kidneys job is almost the same as the livers only that it filters the blood. The arteries and the veins is to take and give the heart blood and take it all around you body.

When the heart pumps blood that has oxygen, the blood goes on the arteries. then the air inside the blood goes disappearing and connects to the veins. This connection is called capilaries.