Across
- 2. your body's reaction to your brain needing oxygen
- 6. breathing in
- 7. the body must do this to get oxygen to cells
- 8. carry oxygen to the cells
- 10. the pulling/pushing muscle that makes you breathe
- 14. the gas we need to breathe out
- 15. we have 2 of these breathing organs (the right one is smaller!)
Down
- 1. the gas we need to breathe in
- 3. also known as air sacs
- 4. a nighttime activity when your body needs less oxygen
- 5. the bones that protect the lungs
- 9. breathing out
- 11. lines the respiratory system
- 12. the breathing tube -also known as the windpipe
- 13. your backup breathing system
- 14. the hairs that help to trap dust, bacteria...