Across
- 4. - diaphragm relaxes and decreases thoracic space
- 5. respiration - exchange of gases within cells of the body organs and tissues
- 7. respiration - exchange of gases in lungs
- 8. - serve as a common passageway for both food and air
Down
- 1. - c-shaped cartilage rings with smooth muscle
- 2. - air sacs
- 3. - movement of air
- 6. - voice box