1. The heart pumps oxygen-rich blood to the body. 2. Carbon dioxide moves from bronchioles to bronchi.
3. Air moves through the bronchi into the bronchioles.
4. Blood picks up Carbon dioxide from the body.
5. Breathe in.
6. Alveoli receive oxygen to pass to blood.
7. The heart pumps carbon dioxide-rich blood to the lungs.
8. Nose traps germs in the air.
9. Oxygen passes into the blood.
10. Air moves down the trachea.
11. Alveoli receive carbon dioxide from the blood.
12. Oxygen-rich blood flows to the heart. 13. Carbon dioxide flows
14. Breathe out.
15. Carbon dioxide flows out of the nose and mouth.​