Across
- 4. The muscle involved in breathing.
- 6. ___________system: A collection of organs whose primary function is to take in oxygen and expel carbon dioxide.
- 7. The main respiratory organ that swells and contracts with each inhalation and exhalation.
- 8. The windpipe; a passage through which air moves in the respiratory system.
- 9. Carbon ____________; The gas that you exhale.
Down
- 1. Tiny air sacs through which oxygen is passed into the respiratory system.
- 2. Keeps food and drink out of lungs.
- 3. The chamber at the back of the throat.
- 5. The trachea branches into these inside the lungs.
- 7. This part of the respiratory systems houses the voice box.