Across
- 2. A sheet of muscle that contracts to reduce pressure in the lungs
- 5. The bones that act like a cage and protect the lungs from damage
- 7. The waste gas produced by living cells
- 8. The pair of organs in which gases are exchanged
- 9. The muscles between the ribs that lift the ribcage
Down
- 1. The pair of tubes that go into each lung
- 3. Another name for the windpipe
- 4. The main gas required for respiration to occur
- 6. Grape like single cell thick structures where gases are exchanged