The Beating of the Heart

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Across
  1. 1. the closing of this valve creates the "lub" sound
  2. 4. the relaxation phase of the cardiac cycle
  3. 7. the closing of this valve creates the "dub" noise
  4. 9. the type of signal that coordinates contraction
Down
  1. 1. rather than going directly from the atria to the ventricle, depolarization goes through the ___
  2. 2. this contracts during the P wave
  3. 3. the heart initiates its own contraction meaning it is___
  4. 5. this is how depolarization is spread through the heart (via ___)
  5. 6. the contraction phase of the cardiac cycle
  6. 8. the acronym for what is used to record electrical signals of the heart