Across
- 3. a sheet like muscle beneath the lungs
- 5. a small blood vessel that connects arteries to veins
- 6. cell fragment that helps form blood clots
- 10. a blood vessel that pumps blood to the heart
- 11. upper chamber of the heart
- 12. a lower chamber of the heart
- 13. a tube that transports air to the lungs
Down
- 1. a muscular organ that pumps blood
- 2. a pair of tubes that branch of the trachea
- 4. a blood vessel that pumps blood from heart
- 6. a yellow fluid in which blood is suspended
- 7. air sacs within the lungs
- 8. the main organ in the respiratory system
- 9. cells of the circulatory system that fights disease