Respiratory system

3. Tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged.
4. Gas needed by the body’s cells to produce energy.
7. Another name for the larynx.
9. The throat; passageway for both air and food.
11. Body system that brings oxygen into the body and removes carbon dioxide.
13. Secondary entrance for air when breathing.
15. Bands of tissue in the larynx that vibrate to make sound.
16. The voice box; contains the vocal cords.
19. Waste gas that the body removes when you breathe out.
23. Tiny hair-like structures that trap dust and sweep it out of airways.
24. Two large organs where oxygen enters the blood and carbon dioxide leaves.
25. Also called the windpipe; carries air to the lungs.

1. The act of moving air in and out of the lungs.
2. The process of exchanging gases (oxygen and carbon dioxide) between the body and the environment.
5. The swapping of oxygen and carbon dioxide between alveoli and capillaries.
6. Space inside the rib cage where the lungs expand and contract.
8. A flap of tissue that prevents food from entering the windpipe.
10. Smaller branches inside the lungs that carry air to the alveoli.
12. Small blood vessels that surround alveoli to allow gas exchange.
13. Sticky substance that traps dirt, dust, and germs in the airways.
14. Breathing out carbon dioxide.
17. Bones that protect the lungs and heart.
18. Breathing in oxygen.
20. Two large tubes that carry air from the trachea into the lungs.
21. Main entrance for air; filters, warms, and moistens it.
22. Muscle below the lungs that moves up and down to help breathing.