Across
- 3. A cell that transports oxygen to tissues and carries carbon dioxide away.
- 6. An enzyme that helps control blood pressure through fluid balance.
- 7. A hormone that stimulates production of oxygen-carrying cells in bone marrow.
- 8. The muscular layer responsible for contraction and pumping.
- 11. A cell involved in defending the body against infections and diseases.
- 13. A substance that triggers an immune response.
- 15. A major blood vessel that carries oxygen-rich blood away from the heart.
- 17. A muscular wall that separates the right and left sides, preventing blood mixing.
- 18. Related to circulation between the heart and the rest of the body.
Down
- 1. Related to the lungs or blood flow between the heart and lungs.
- 2. A lower chamber that pumps blood either to the lungs or the rest of the body.
- 4. A protein that binds oxygen for transport through the body.
- 5. A protective sac that encloses the heart and reduces friction.
- 9. An external flap that increases the capacity of an upper heart chamber.
- 10. The upper chambers that receive returning blood.
- 12. cava Large veins that return oxygen-poor blood to the heart.
- 14. A cell active in allergic responses and fighting parasites.
- 16. A protein that binds specifically to a foreign substance to help remove it.
- 18. Node A group of specialized cells that generate electrical impulses to regulate heartbeat.