Figure 2. How Does the Heart Works: Path of blood flow through the heart2  
Blood Flow of the Heart Right Heart receives blood from the body and pumps it through the pulmonary artery to the lungs where it picks up oxygen.

Left Heart receives oxygen-rich blood from the lungs and pumps it through the aorta to the body.
  This figure is reproduced with special permission from The American Heart Association, Your Heart and How It Works, © 2005