Respiratory System

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Across
  1. 3. Muscle located under the lung
  2. 7. Bone structure which protects the heart and lungs
  3. 8. Main organ of the respiratory system
Down
  1. 1. Filters the air we inhale and branches into the windpipe
  2. 2. Letting air out of the lungs
  3. 4. Taking air into the lungs
  4. 5. A substance that moistens the air as well as trapping foreign substances
  5. 6. tubes Tubes which leads from windpipe to each lung
  6. 9. Allows air to enter and leave the body