The Respiratory System

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Across
  1. 5. what we breathe out
  2. 8. found at the end of the trachea
  3. 10. organ that collects air
  4. 11. small air tubes
  5. 12. when gas is exchanged between the alveoli and lung capillaries
Down
  1. 1. any of the fine branching blood vessels
  2. 2. pipe that sends air to lungs
  3. 3. muscle that inflates and deflates the lungs
  4. 4. What we use to breathe
  5. 6. each of a series of slender curved bones
  6. 7. Smelling source
  7. 9. tiny air sacs at the end of the bronchioles