Across
- 2. dioxide: a gas that is a waste product of cells when they burn food.
- 6. hair-like structures found in the air passageways of the respiratory system.
- 7. the basic unit of any living thing. Some living things consist of only a single cell, while others are composed of trillions of cells
- 10. a disease that damages the alveoli, making it difficult to get enough oxygen.
- 11. cords: two folds of tissue in the larynx that vibrate when air passes over them and produce sound, including the basic sounds of speech.
- 12. to take air in and expel it out of the lungs.
- 15. tiny blood vessels.
- 17. breathe in.
- 19. a cavity behind the nose and mouth that leads to the trachea and oesophagus.
- 20. rate: the rate, or number of breaths per minute, at which we breathe.
- 22. the tube that carries food from the back of the throat to the stomach.
- 23. two bag-like organs that fill most of the chest. The lungs draw in air through the trachea and bronchi.
- 24. a part of the respiratory system between the pharynx and the trachea. It houses the vocal cords.
Down
- 1. pair of tubes between the trachea and the lungs.
- 3. a large muscle below the ribs that helps a person breathe.
- 4. a breathing disorder in which the air passageways in the lungs constrict, causing shortness of breath.
- 5. one of the lung's smallest air passageways.
- 8. the movement of oxygen from the atmosphere to cells and carbon dioxide from cells to the atmosphere.
- 9. tiny air sacs in the lungs.
- 13. breathe out.
- 14. the air passageway between the pharynx and the bronchi.
- 16. a flap of tissue that prevents food from going down the trachea rather than the oesophagus.
- 18. system: the group of organs that take in oxygen from the air and release carbon dioxide.
- 21. a sticky substance in the nose that traps dirt, dust and other particles.
- 22. a gas in air that humans and most living things need to live.
- 24. capacity: the volume of air that the lungs can hold.