Respiratory System

2. the chest
3. take air into the lungs and then expel it
4. oval-shaped cavity inside the skull
6. slimy substance
9. tiny air sacs of the lungs
12. absense of oxygen
14. blood vessels that carry blood from and to the heart
16. the windpipe
17. an infection that inflames the air sacs in one or both lungs
18. fluid that transports oxygen and nutrients to the cells and carries away carbon dioxide and other waste products
21. colorless, odorless, gaseous element

1. structure that separates the thoracic (chest) and abdominal cavities in mammals
3. A large airway that leads from the trachea to a lung.
5. the act of drawing air into the lungs
7. referred to by its formula CO2
8. large, air-filled space above and behind the nose in the middle of the face
10. membrane-lined cavity behind the nose and mouth, connecting them to the esophagus
11. the tube that connects the pharynx (throat) with the stomach
13. a wall, dividing a cavity or structure into smaller ones
15. the voice box
19. pair of organs situated within the rib cage
20. major air passages of the lungs which diverge from the windpipe