Across
- 2. pumps blood throughout the heart
- 3. air passage from trachea to lungs
- 5. air sacks in the lungs
- 7. body system of breathing
- 9. to inhale
- 10. inside trachea
- 11. to exhale
- 12. body system that circulates blood
- 15. another word for breathing
Down
- 1. opposite of oxygen
- 4. cardiovascular exercise
- 6. opposite of carbon dioxide
- 8. wind pipe
- 13. add oxygen to blood
- 14. always transporting around the body to help stay alive