Across
- 3. tiny air sacs in the lung where gas exchange occurs
- 4. muscle that helps us breathe
- 6. tiny branches in with the bronchus divides
- 7. wind pipe
- 8. when air leave the lungs
- 9. sticky substance that helps trap particles and microbes
Down
- 1. little hairlike organelles
- 2. cells responsible for carrying oxygen
- 5. when oxygen enters the lungs