The Heart

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Across
  1. 1. Blood vessel that is one cell thick
  2. 5. Lower chamber on the right
  3. 6. Upper chamber on the left
  4. 7. Carries blood to the heart
  5. 8. Prevent blood from flowing backwards
Down
  1. 2. Lower chamber on the left
  2. 3. Upper chamber on the right
  3. 4. Divides the right and left side
  4. 9. Carries blood away from the heart