Across
- 4. Our _____ expand and contract like balloons as we breathe
- 5. What scientists call your windpipe
- 9. If you know that "respiration" means "_____", then you can already guess what the respiratory system does
- 10. To blow up like a balloon
- 11. We breathe out _____ dioxide, and plants take it in
Down
- 1. Little tubes in your lungs; Clue: Bronchitis
- 2. To become small again after expanding
- 3. Sacs inside the lungs that get oxygen and carbon dioxide to and from the blood as we breathe in and out
- 6. The _____ system is a group of organs that work together to make sure you can breathe
- 7. Plants release _____, and we breathe it in
- 8. The muscle that allows your lungs to expand and contract; it shrinks as your lungs grow and it grows as your lungs shrink