Circulatory System

1. Enable exchange of oxygen with body.
4. Veins which connect with the left lung.
6. Receives blood low in oxygen from the body and then empties the blood into the right ventricle.
7. A semilunar valve between the aorta and the left ventricle of the heart.
15. Pumps blood throughout your body.
16. Tiny air sacs at the end of the bronchioles.
18. This system delivers oxygen and nutrients to cells and takes away wastes.
19. Pumps blood low in oxygen to the lungs.
20. The main artery of the body.
21. Transport blood cells throughout your body.

2. Normally acts like a one-way door from your heart's right ventricle to the lungs.
3. Carry blood away from the heart.
5. Transporting oxygen and nutrients to the lungs and tissues.
8. Carry air in and out of your lungs.
9. Receives blood full of oxygen from the lungs and then empties the blood into the left ventricle.
10. Help the body fight infection and other diseases.
11. Opens to allow blood to leave the heart from the left ventricle through the aorta and the body.
12. Carry blood from the right side of the heart through to the capillaries of the lungs.
13. A condition in which the heart beats with an irregular or abnormal rhythm.
14. Carry blood toward the heart.
17. Vein that carries blood to the heart from other areas of the body.