The Respiratory System

4. The physical movement of air in and out of the lungs (inhaling/exhaling).
5. The air that remains in the lungs after a forceful exhale.
9. A flap that prevents food from entering the trachea during swallowing.
10. Double-layered membrane surrounding each lung.
13. Breathing in; diaphragm contracts and air flows into the lungs.
16. The voice box; located above the trachea and involved in sound production and protecting the airway.
20. Smaller branches of the bronchi that lead to the alveoli.
22. Breathing out; diaphragm relaxes and air is pushed out of the lungs.
23. known as the windpipe that connects the larynx to the bronchi and allows air passage to the lungs.
24. Rapid or deep breathing that can lower CO₂ levels in the blood.
25. The process of gas exchange: taking in oxygen and releasing carbon dioxide.

1. Carries oxygenated blood from the lungs to the heart.
2. Sticky fluid produced in the airways that traps dust, pathogens, and other particles.
3. Air-filled spaces in the skull that help lighten the head and moisten inhaled air.
6. A dome-shaped muscle under the lungs that helps with breathing.
7. Hair-like structures in the airways that help move mucus and debris out of the lungs.
8. Carries deoxygenated blood from the heart to the lungs.
11. The throat; a passage for both air and food.
12. The amount of air inhaled or exhaled during normal breathing.
14. Two large respiratory organs where gas exchange takes place.
15. Waste gas produced by cells and exhaled from the lungs.
17. The two main air passages that branch from the trachea into each lung.
18. Tiny air sacs in the lungs where gas exchange occurs
19. A chronic respiratory condition where airways become inflamed and narrowed.
21. Essential gas inhaled into the lungs and transported by the blood to body tissues.