BIOLOGY REVIEW

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Across
  1. 3. oxygen and ... are needed for aerobic respiration
  2. 8. the process oxygen is inhaled and carbon dioxide is exhaled is called
  3. 11. blood cells that fight infections and protect the body from germs
  4. 13. to prevent backflow of blood
  5. 15. substance that make person very difficult for a person to quit smoking
  6. 17. largest artery in the human body
  7. 18. tiny air sacs in the lungs where oxygen enters the blood
  8. 20. smoking increases the risk of .... eye problem
Down
  1. 1. carries oxygenated blood from the lungs to the heart
  2. 2. tube that carries air from the throat to the lungs
  3. 4. tiny blood cell fragments that help stop bleeding by forming clots
  4. 5. layered membrane that surrounds the lungs and provides lubrication
  5. 6. Blood vessel that leaves the right ventricle to travel to the lung
  6. 7. chamber of the heart that pump blood to the entire body
  7. 9. type of blood vessel for gas exchange and extremely thin
  8. 10. bronchi transport air from … to lungs
  9. 12. bronchi to become restricted (get smaller) so air can't get to the lungs.
  10. 14. muscle below the lungs that helps you breathe in and out
  11. 16. exercise that strengthens the heart and improves blood circulation
  12. 19. anaerobic respiration need the substance