Across
- 2. carries blood away from the heart
- 6. smallest blood vessel
- 10. Allows air to pass to and from lungs
- 12. Tiny finger-shaped structures
- 14. lower chamber of the heart
- 15. where digestion begins
Down
- 1. Liquid part of blood
- 3. A muscular tube
- 4. tiny sacs of lung tissue
- 5. Airways in the lungs that lead from the bronchi to the alveoli
- 7. The passages that direct air into the lungs
- 8. a cell fragment
- 9. large muscular sac
- 11. upper chamber of the heart
- 13. carries blood back to the heart