The Heart

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Across
  1. 3. Chamber at the bottom
  2. 4. Name of the system
  3. 6. What carries blood away from the heart
  4. 8. What the walls of the heart are made from
  5. 9. Number of chambers in the heart
Down
  1. 1. A shortening or tensing of the muscle
  2. 2. Chamber at the top
  3. 5. What returns blood to the heart
  4. 7. Organ that pumps blood