Ch 16: Circulatory System

3. small knobs of tissue that filter lymph and trap bacteria in the fluid.
5. the process where molecules of high concentration move to areas of low concentration.
9. a force that blood exerts against the walls of blood vessels.
11. a hollow, muscular organ that pumps blood throughout the body.
12. the body's disease fighters
17. these pick up oxygen in the lungs and deliver them to cells throughout the body.
18. a condition in which an artery wall thickens as a result of build up of fatty materials.
21. a network of veinlike vessels that returns the fluid to your bloodstream.
22. a group of heart cells in the right atrium that sends out signals that make your heart muscle contract, or beat.
23. blood vessels that carry blood away from the heart.

1. smaller arteries that branch off the aorta and carry blood to the heart.
2. also known as the circulatory system. It's made up of the heart, blood vessels, and blood.
4. an instrument used to measure blood pressure.
6. the alternating expansion and relaxation of an artery wall as blood travels through an artery.
7. a condition also known as high blood pressure.
8. cell fragments that prevent loss of blood by forming blood clots when a vessel is cut.
10. teh fluid collected by the lymphatic system.
13. the two lower chambers of the heart.
14. blood vessels that carry blood back to the heart.
15. tiny, narrow vessels where substances are exchanged between blood and body cells.
16. the liquid part of the blood.
19. a protein on red blood cells. It's positive or negative.
20. the two upper chambers of the heart.