Across
- 2. Tiny air sacs in the lungs where gas exchange occurs (7)
- 4. The protein in red blood cells that binds to oxygen (10)
- 6. The voice box, located at the top of the trachea (7)
- 7. The windpipe that connects the larynx to the bronchi (7)
- 10. The chemical process by which cells obtain energy from glucose and oxygen (11)
- 12. The primary organ of respiration in mammals (4)
Down
- 1. The membrane that covers the lungs and lines the chest cavity (8)
- 3. The process of moving air into and out of the lungs (11)
- 5. The muscle that aids in breathing by contracting and relaxing (8)
- 8. The flap of cartilage that prevents food from entering the trachea (8)
- 9. Small tubes in the lungs that branch from the bronchi (9)
- 11. The primary respiratory pigment in animals (8)