Across
- 3. The muscle beneath the lungs that helps breathing
- 8. The main breathing organs
- 9. The waste gas removed when breathing out
Down
- 1. The gas needed by body cells for energy
- 2. The tube that carries air from the throat to the lungs
- 4. The process of exchanging gases in the body
- 5. Large tubes connecting the trachea to the lungs
- 6. Small tubes branching from the bronchi
- 7. Tiny air sacs where oxygen enters the blood