Respiratory System
Across
- 3. gas that diffuses into blood
- 5. voice box
- 7. muscle that contracts when we inhale
- 9. breathing tube
- 11. to breathe in
- 12. smaller tubes that lead to alveoli
Down
- 1. back of throat
- 2. blood vessels that surround the alveoli
- 4. two tubes that split off the trachea
- 6. moisten and warm the breath
- 8. small sacs that inflate when we inhale
- 10. to breathe out