Across
- 2. A dome-shaped muscle that controls breathing.
- 7. The body system that allows breathing and gas exchange.
- 9. Where air is warmed, moistened, and filtered.
- 11. The tube that carries air from the throat to the lungs.
- 12. Tiny air sacs where oxygen and carbon dioxide are exchanged.
- 13. A gas the body needs to release energy from food.
- 14. The main organs of the respiratory system.
- 15. To breathe air out of the lungs.
Down
- 1. A waste gas produced by cells.
- 3. Sticky substance that traps dirt and bacteria.
- 4. Tiny hair-like structures that sweep out dust and germs.
- 5. To breathe air into the lungs.
- 6. Smaller branches inside the lungs that lead to alveoli.
- 8. The movement of oxygen into the blood and carbon dioxide out.
- 10. Two large tubes that branch from the trachea into each lung.