Heart and Lungs

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Across
  1. 5. The upper chambers of the heart are the -----. (5)
  2. 7. The largest artery in the body, carries oxygenated blood to the body tissues. (5)
  3. 8. This blood vessel has a wall just one cell thick to allow exchange of substances. (9)
  4. 9. This vessel carries deoxygenated blood back to the heart from the body tissues. (4,4)
  5. 11. The muscular sheet which contracts and flattens to help us breathe in. (9)
  6. 12. This is the molecule in red blood cells which absorbs oxygen. (11)
  7. 15. These protect the lungs from damage.(4)
  8. 16. These prevent backflow of blood in the veins and heart (6)
  9. 18. Tiny little branches which split off from the bronchi. (11)
  10. 20. This vessel carries oxygenated blood to the heart from the lungs. (9,4)
Down
  1. 1. This vessel carries deoxygenated blood to the lungs from the heart. (9,6)
  2. 2. The left side of the heart is on the ----- of the diagrams. (5)
  3. 3. The largest tube in your airways. (7)
  4. 4. This is what we call the molecule in red blood cells when it has absorbed oxygen. (14)
  5. 6. The tiny air sacs where gas exchange takes place. (7)
  6. 10. A blood vessel which has a thick layer of muscle and elastic tissue. (6)
  7. 13. We fill these with air when we breathe in. (5)
  8. 14. A blood vessel which has a thin muscle and elastic wall and contains valves. (4)
  9. 17. This type of blood cell protects us against disease. (5)
  10. 19. This type of red blood cell carries oxygen. (3)
  11. 21. These are the lower chambers of the heart. (10)