The Heart

3. carries deoxygenated blood to the right atrium of the heart.
4. receive oxygenated blood from the lungs and drain into the left atrium.
5. carries deoxygenated blood from the heart to the lungs.
6. pumps the oxygen-rich blood through the aortic valve.
10. Blood collects into the right atrium, and it must flow through here before entering the right ventricle.
11. carry deoxygenated blood back to the heart.
12. Blood from the heart flows through these and collects oxygen while it expels carbon dioxide.
15. receives deoxygenated blood from the body through the vena cava and pumps it into the right ventricle.

1. allows blood to flow from the heart's lower left ventricle into the aorta.
2. pumps the blood up through the pulmonary valve.
5. the semi-lunar valve of the heart that lies between the right ventricle and the pulmonary artery.
7. Oxygen-rich blood from the lungs enters here and the blood is then pumped into the left ventricle chamber of the heart through the mitral valve.
8. allow oxygen, nutrients, carbon dioxide and waste products to pass to and from the tissue cells.
9. When the left ventricle contracts, this valve closes. This forces the blood to flow from the left ventricle.
13. carries blood from the heart.
14. carry blood from the heart to all the organs and muscles of the body.