Respiratory System

2. A colorless, odorless, gaseous element constituting about one-fifth of the volume of the atmosphere and present in a combined state in nature
4. Where the vocal cords are located.
8. The drawing of air into the lungs
10. Preventing the entrance of food and drink into the larynx
14. membranous or ligamentous wall separating two cavities or limiting a cavity
16. The act of breathing out.
17. Minute hairlike organelles, that line the surfaces of certain cells
18. A bronchus or any of its ramifications or branches

1. Either of two external openings of the nasal cavity in vertebrates that admit air to the lungs and smells to the olfactory nerves
3. An air cell of the lungs, formed by the terminal dilation of tiny air passageways.
5. A colorless, odorless, incombustible gas, CO 2, present in the atmosphere and formed during respiration
6. One of a series of curved bones that are articulated with the vertebrae and occur in pairs.
7. Several groups of muscles that run between the ribs.
9. The tube or cavity, with its surrounding membrane and muscles, that connects the mouth and nasal passages with the esophagus.
11. Either of the two respiratory organs in the thorax.
12. A muscular passage connecting the mouth or pharynx with the stomach.
13. Either of the two main branches of the trachea
15. A action of breathing
19. The cavity of this part of the body containing the stomach.
20. One of the air-conveying tubes of the respiratory system.