Across
- 5. Another name for voice box
- 6. Gas inhaled by humans
- 7. major air passages of the lung which branch from the windpipe
- 10. Upper chambers of the heart
- 12. Smallest blood vessels in the vascular system
- 13. Blood vessels which carry blood towards the heart
- 14. Gas which the arteries transport to cells
Down
- 1. Gas exhaled by humans
- 2. vein and artery which behave opposite to other veins and arteries
- 3. Lower chambers of the heart
- 4. Another name for windpipe
- 8. Muscle below lungs which plays a role in respiration
- 9. Organ which pumps blood
- 11. bones which protect lungs and heart