The Respiratory System
Across
- 6. tiny blood cells
- 7. net passive movement
- 8. colorless acid with gas
- 11. an organ that collects air
- 12. A pipe that sends air to the lungs
Down
- 1. air sac
- 2. small air tubes
- 3. Something you use to smell things
- 4. chemical that has O
- 5. splits the air into each lungs
- 9. bones that cover lungs
- 10. a muscle that inflates and deflates lungs