Across
- 5. divides heart sides
- 6. exchange gases
- 9. regulates heartbeat rate
- 11. transports nutrients
- 13. heart muscle relaxation
- 14. prevent blood backflow
- 15. heart muscle contraction
- 16. carry blood away
- 18. small blood vessels
- 20. initiates heart impulse
Down
- 1. fights infection
- 2. pumps blood out
- 3. triggers heart contraction
- 4. lower heart chambers
- 7. upper heart chambers
- 8. controls heart rhythm
- 10. return blood back
- 12. clot blood
- 17. allows chamber filling
- 19. carries oxygen