Across
- 3. Name of the arteries that supply the heart with oxygenated blood
- 8. A medicine that reduces the level of bad cholesterol in the blood
- 10. Name of a cell that defends against infection
- 11. Name of a cell that has no nucleus
- 12. Humans have a ______ circulatory system
- 15. The liquid that carries everything in the blood
- 16. Name for small fragments of cells that help blood clot
- 17. Blood vessel that carries the blood to the heart
Down
- 1. Number of chambers the heart has
- 2. A pumping organ that keeps blood flowing around the body
- 4. Name of the substance formed when haemoglobin binds to oxygen
- 5. Blood vessel involved in the exchange of materials at the tissues
- 6. The sinus node is the natural _________ of the heart
- 7. Name of the chambers at the bottom of the heart
- 9. Name for tubes that are inserted inside arteries to keep them open
- 13. Blood vessel that carries blood away from the heart
- 14. A structure that prevents blood flowing backwards