the respiratory system
Across
- 1. windpipe
- 3. airway
- 5. muscle for inflating
- 7. organ that collects air
- 10. protect organs
- 11. where you get air from
- 12. a heavy gas
Down
- 2. air sacs that exchange oxygen
- 4. blood vessels
- 6. movement of molecules
- 8. hole to breathe from
- 9. small air tubes