Respiratory System

3. two branches of the trachea that each leads to a lung
5. System a collection of organs whose primary function is to take in oxygen and expel carbon dioxide; the organs of this system include the lungs, the throat, and the passageways that lead to the lungs
7. the smallest of the tubes that the bronchi branch off to which are also lined with cilia and mucus
9. the process of releasing air from the lungs
10. a large skeletal muscle that separates the thoracic cavity from the abdominal cavity
11. a cartilaginous tube called the windpipe
12. clusters of air sacs at the end of bronchioles

1. the site of gas exchange between the atmosphere and the blood
2. Respiration the exchange of gases between the atmosphere and the blood
4. Respiration the exchange of gases between the blood and the cells of the body
6. the process of taking in air into the lungs
8. a tube at the back of the nasal cavities and the mouth
9. a flap of cartilage
13. the upper end of the trachea