| A | B |
|---|
| Vena Cava | carries blood to the heart from the body |
| Pulmonary Artery | carries blood to the lungs |
| Pulmonary Vein | carries blood from the lungs to the heart |
| Aorta | carries blood to the body from the heart |
| Cardiac muscle | never tires and always works |
| Ventricles | the top part of the heart |
| Atria | the bottom part of the heart. |
| De-oxygenated blood | blood without oxygen |
| Oxygenated blood | blood with oxygen in it. |
| Valves | control the flow of the blood and its direction. |
