Across
- 2. A strong muscle just below the lungs
- 4. The blood is made up of both red and _____ blood cells
- 8. The voice box
- 11. A large blood vessel
- 12. An upper chamber of the heart
- 13. The organ that supplies blood
- 14. Another term for gaseous exchange
- 16. Breathing in
- 18. The organ we use to breathe
- 19. A lower chamber of the heart
Down
- 1. The wind pipe
- 3. The only veins that carry oxygenated blood
- 5. When we breathe out
- 6. It divides the heart into two sides
- 7. Smaller than bronchi
- 9. Tubes at the lower end of the trachea
- 10. Small, thin walled blood vessels
- 15. The second phase of the heartbeat
- 17. The first phase of the heartbeat
- 19. The tubes that carry blood back to the heart