Respiratory system

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Across
  1. 3. Tiny blood vessels where gas exchange occurs.
  2. 5. The membrane that surrounds the lungs to reduce friction.
  3. 7. The tiny air sacs in the lungs where gas exchange occurs
  4. 8. The gas inhaled during breathing and delivered to muscles.
  5. 9. The gas removed from the blood during respiration
  6. 11. The main airway connecting the throat to the lungs
  7. 12. Small air passages that deliver air to the alveoli.
  8. 13. The process of breathing out
Down
  1. 1. The process of breathing air into the lungs.
  2. 2. The part of the brain responsible for controlling breathing.
  3. 4. The voice box that contains the vocal cords
  4. 6. Blood vessel that carries oxygenated blood from the lungs to the heart
  5. 10. The muscle responsible for breathing