Cardiovascular Crossword

2. muscular middle layer and is the thickest layer
3. platelets, usually described as fragments or pieces of cells because they lack nuclei and vary in shape and size
6. red blood cells, are produced in the red bone marrow at a rate of about one million per minute
10. complex protein composed of the protein molecule called globin and the iron compound called heme
12. 90 percent water with many dissolved, or suspended, substances
13. transportation system of the body
16. Connect arterioles with venules, the smallest vein
17. receives blood as it returns from the body cells
20. located between the left atrium and left ventricle
22. carry blood away from the heart
23. blood vessels that carry blood back to the heart
24. abnormal heart rhythms and can be mild to life-threatening
25. followed by a period of ventricular contraction

1. receives blood from the right atrium and pumps the blood into the pulmonary artery
4. brief period of rest
5. double-layered membrane or sac that covers outside of the heart
7. muscular wall that separates the heart into a right side and a left side
8. receives blood from the left atrium and pumps the blood into the aorta for transport to the body cells
9. smooth layer of cells that lines inside of the heart
11. tissue
14. largest artery in the body, located between the left ventricle and the aorta
15. allows blood to flow into the lungs and prevents blood from flowing back into the right atrium
18. carries blood into the lungs
19. white blood cells
21. receives oxygenated blood from the lungs