Across
- 2. how oxygen flows throughout the body
- 4. the study of lung diseases
- 6. external body part that is used to inhale and exhale
- 7. A common lung disease which is caused by an infection of the lungs.
Down
- 1. the gas that exits the respiratory system
- 3. the type of gas that is the main intake for the respiratory system
- 5. the only organ that can float on water