Circulatory System

2. when the heart muscle contracts
3. when the heart muscle relaxes
6. very small blood vessel that branches off from your artery and carries blood away from your heart to your tissues and organs
11. blood vessels located throughout your body that collect oxygen-poor blood and return it to your heart
13. the system of transportation that shunts de-oxygenated blood from the heart to the lungs to be re-saturated with oxygen
14. responsible for clotting blood
16. very small blood vessels that connect your capillaries with your veins throughout your body
18. a fibrous sac that encloses the heart
23. provides the functional blood supply to all body tissue
25. the smallest type of blood vessel

1. combats antigens
4. thin walled chambers that receive blood from the veins
5. tip or summit of an organ
7. red blood cells (rbc)
8. protein inside rbc that carries oxygen from the lungs to other organs
9. white blood cels (wbc)
10. carries blood cells
12. the muscle layer of the heart
15. toxins or bacteria that come from outside the body
17. the blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body
19. thin, smooth tissue that makes up the lining of the chambers and valves of the heart
20. amount of whole blood that is made up of rbc
21. muscular chamber that pumps blood out of the heart and into the circulatory system
22. liquid connective tissue
24. outermost, protective layer of the heart