Across
- 4. Air intake into the lungs.
- 6. Tiny blood vessels surrounding the alveoli.
- 7. Main organs of the respiratory system.
- 9. Movement of gases across membranes.
- 10. Movement of air in and out of the lungs
- 12. Thin layer that allows the passage of gases.
- 13. Branches of the trachea within the lungs.
- 14. Gas exchange in the lungs.
Down
- 1. Air exits the lungs.
- 2. Small lung structures where gas exchange occurs.
- 3. Process of oxygen intake and carbon dioxide output.
- 5. Protein that carries oxygen in red blood cells
- 8. Gas in the air that carries blood.
- 11. Tube that carries air to the lungs.