Respiratory System

4. The 2 large airways branching from the trachea.
7. Cells do this and it causes carbon dioxide levels in the blood to increase.
10. This gradient is the cause of gas exchange in the respiratory system.
12. The diaphragm does this when we inspire.
13. These are the site of gas exchange in the lungs.
15. (6, 9) Gasses are exchanged in the respiratory system using this process.
16. (4, 2, 3) Air will always move this way due to pressure.
17. (7, 5) The lubricant, holds lungs to pleural membranes and in turn the ribs.
18. These muscles are found in between the ribs.

1. Breathing out is also called this.
2. The respiratory surface must be this for gases to dissolve.
3. (9, 8) These carry deoxygenated blood from heart to lungs.
5. Made of bone for the protection of the lungs.
6. Pressure in the lungs _____________ when we inhale.
8. The heart does this to help maintain concentration differences at the alveoli.
9. (5, 6) Warms, filters and moistens the air you breathe.
11. The shared area of respiratory and digestive system.
14. The flap of cartilage tissue covering trachea when swallowing.
19. The walls of the alveoli must be this for gas exchange to occur.