Across
- 3. from which the two bronchi branch off
- 6. Breathing in
- 7. Waste product of cellular respiration
Down
- 1. process of taking air into and expelling it from the lungs
- 2. dome-shaped muscles separating the lungs from the stomach
- 4. reacts with oxygen to release energy
- 5. what happens to the diaphragm during inhalation