Across
- 3. A chemical compound with the chemical formula CO2
- 4. A breathing condition in which it becomes difficult to breath
- 6. A dome shaped muscle that separates the thorax from the abdomen
- 8. A colorless, odorless gas that makes up about 21% of the Earth’s atmosphere
Down
- 1. A pair of organs that supply the body with oxygen and remove carbon dioxide from it
- 2. Curved bones in a persons chest that connect to the spine
- 5. A tube that conveys air to and from the lungs
- 7. The area of the body that contains the digestive organs