Across
- 2. breathing out
- 4. Where gaseous exchange takes place in the lungs
- 6. Muscle under ribs that help us breathe
- 10. drug in cigarettes
- 11. gas we breathe in
- 12. how oxygen and carbon dioxide move through alveoli
- 13. tiny hair like parts that keep lungs clean
Down
- 1. wind pipe
- 3. pipe that splits off trachea to each lung
- 5. breathing in
- 7. muscles between ribs
- 8. branches of the bronchus
- 9. protect lungs