Across
- 3. vocal cords
- 4. the food tube
- 5. back of the throat
- 6. breathing in
- 9. chemical that triggers breathing
- 12. muscle that pulls lungs down
- 14. pulls air into lungs
- 15. when bronchus gets small
- 17. percentage of oxygen in the air
Down
- 1. what the muscles do to force air out
- 2. percentage of oxygen in exhaled air
- 4. breathing out
- 7. controls breathing
- 8. the windpipe
- 9. protects the throat
- 10. muscles that raise chest
- 11. the flap
- 13. where gas exchange takes place
- 16. left and right main