Respiratory/Circulatory System

2. very tiny blood vessels
4. the tube that blood is pumped through to get into the right side of the heart, and out of the lungs
5. blood cells that prevent disease
8. cells in the circulatory system that prevent blood clotting
9. a muscle inside your body that pumps blood through 4 chambers nonstop
11. the tube in which humans obtain oxygen from
12. the system by which oxygen is taken into the body
16. the two major respiratory organs in the human body
18. the tube that blood is pumped through to get out of the left side of the heart, and into the lungs
19. tubes that blood go through to get to cells in the body
20. how fast your heart pumps blood.

1. one of four heart structures that open and close in order for blood to get from chamber to chamber
2. the system by which blood is circulated through the body
3. 600,000,000 air sacs in the lungs
6. contracts when inhaling, relaxes when exhaling
7. one of two lower chambers in the heart
10. the main branches of the trachea
12. microscopic disks that carry blood to the cells and tissues
13. things that increase the chance of a heart attack
14. one of two upper chambers in the heart
15. the water part of blood
17. the fluid that circulates in the circulatory system