Circulatory System

2. The top chamber of the heart that receives blood coming into the heart.
3. The rhythmic movement of blood in arteries caused by the heartbeat.
8. A protein in red blood cells that binds to and transports oxygen.
9. A blood vessel that transports blood low in oxygen back to the heart.
10. The straw-colored fluid in blood that carries nutrients and waste products.
11. The ____ (Electrocardiogram) records the heart's electrical activity over time.
13. The largest blood vessel that carries oxygenated blood from the heart to the body.
15. The ____ artery sends blood to the lungs to pick up oxygen.
17. The muscular wall separating the left and right sides of the heart.
18. The ____ blood cell defends the body against infections and pathogens.
19. The ____ vein returns oxygen-rich blood to the heart from the lungs.
20. The ____ cycle describes the series of steps in one heartbeat.
21. The ____ cava is the vein that brings deoxygenated blood to the heart.
22. A part of the blood involved in clotting to seal wounds.
24. The phase of the heartbeat when the heart contracts and pumps blood.

1. The phase of the heartbeat when the heart relaxes and refills with blood.
4. The ____ artery provides blood and oxygen to the heart muscle itself.
5. A structure in the heart or veins that stops blood from flowing backward.
6. Blood ____ measures the force of blood against the walls of arteries.
7. The system that moves blood through the heart, lungs, and body.
8. The central organ of the circulatory system that pumps blood throughout the body.
12. The bottom chamber of the heart that pushes blood out to the body or lungs.
14. A vessel that carries blood rich in oxygen away from the heart.
16. Microscopic blood vessels where oxygen and nutrient exchange occurs.
23. The ____ blood cell carries oxygen to body tissues and removes carbon dioxide.