Across
- 4. A powerful muscular pump.
- 9. Lines the interior of the heart and heart valves.
- 11. Secrete factors that affect the size of blood vessels, reduce blood clotting, and promote the growth of blood vessels.
- 12. A fibrous and membranous sac, surrounds the heart.
- 13. The beat pf the heart as felt through the walls of arteries.
- 15. smaller branches of arteries.
Down
- 1. Two upper chambers of the heart.
- 2. Lower chambers of the heart.
- 3. microscopic vessels carry nutrient-rich, oxygenated blood from the arteries and arterioles to the body cells.
- 5. Means wall.
- 6. Largest single artery in the body.
- 7. The______ arteries supply blood to the head and neck.
- 8. Prevent the backflow of blood and keep the blood moving in one direction.
- 10. Muscular layer of the heart wall, is its thickest layer.
- 14. Blood pressure is extremely low compared with pressure in arteries.