Across
- 4. The bony framework of the thoracic cavity
- 5. Tiny air sacs at the end of the bronchioles
- 7. Air
- 8. A colorless, odorless gas
- 10. A tiny branch of air tubes in the lungs
- 11. A long, U-shaped tube
- 12. The movement of molecules
Down
- 1. The major muscle of respiration
- 2. Allow us to breathe
- 3. A thin tube
- 6. For breathing and smelling
- 9. A large airway