Respiratory System

1. Lungs are separated from the abdominal cavity by a muscle called the _________.
4. Eventually, the bronchioles and end in tiny air sacs with a single cell layer.
6. Alveoli are surrounded by theses.
8. Breathing out
10. During inhalation the epiglottis lifts up so that air passes over the larynx and into the _______
11. ___________ brings oxygen into the lungs and eliminates Co2
14. Another name for the pharynx.
16. Look like small clusters of grapes.
18. The epiglottis prevents _________ from entering the airway during swallowing.
19. Another name for trachea.
21. These are spongy tissues filled with alveoli, blood vessels, and nerves.

2. Breathing In
3. The respiratory system is divided into the _____ respiratory tract and the lower respiratory tract.
5. The bronchus enters the lung and further divides into small branches called ___________.
7. Every Cell Needs This To Survive
9. Respiration involves inhalation & __________.
12. A piece of cartilage acts like a lid over the larynx.
13. Air enters the nose and passes into the ______.
15. The right lung has _____ lobes.
17. The voice box.
20. Each lung is covered by a two-layered sac called.