Across
- 2. a dome-shaped muscular partition
- 4. known as CO2
- 7. A tiny branch of air tubes in the lungs
- 8. rings called cartilage
- 10. you use it to smell
- 11. branching blood vessels
Down
- 1. the spreading of something more widely
- 3. they puff up when we breathe
- 5. you breathe it
- 6. tiny air sacs in the lungs
- 7. any of the major air passages of the lungs
- 9. like a cage for your lungs