Across
- 2. muscle that inflates and deflates the lungs
- 4. what we breathe out
- 7. small air tubes
- 8. pipe that sends air to lungs
- 10. Smelling source
- 11. any of the fine branching blood vessels
Down
- 1. when gas is exchanged between the alveoli and lung capillaries
- 3. organ that collects air
- 5. What we use to breathe
- 6. tiny air sacs at the end of the bronchioles
- 7. found at the end of the trachea
- 9. each of a series of slender curved bones