Across
- 5. white blood cell.
- 6. vein that does not meet up with the vena cava.
- 12. heart valve.
- 13. supply blood to heart.
- 15. heart muscle.
- 16. when heart is relaxed.
- 17. cardiac muscle in short oxygen supply.
- 18. influence of carbon dioxide concentration on heart rate.
- 20. blood clot.
Down
- 1. component of blood.
- 2. Scientist who demonstrated the one-way action of valves.
- 3. inorganic element in blood.
- 4. left atrium receives from.
- 7. measurement of heart activity.
- 8. blood vessel.
- 9. carry blood away from heart.
- 10. carry deoxygenated blood.
- 11. involved in blood clotting.
- 14. controls heart beat.
- 19. circulatory system in humans.