The Heart part 3

  1. P-wave
    is a small upward deflection on the ECG it represents atrial depolarization which spreads from the SA nodes through contractile fibers in both atria
  2. QRS complex
    begins as downward deflection, continues as a large upright, triangular wave and ends as a downward wave.  It represents rapid ventricular depolarization, as the action  potential spreads through ventricular contractile fibers
  3. T-wave
    a dome shaped upward deflection.  It indicates ventricular re polarization and occurs just as the ventricles are starting to relax.
  4. systole
    refers to the phase of contraction.  the atria and ventricles depolarize and then contract at different times.
  5. diastole
    the phase of relaxation
  6. cardiac cycle
    includes all the events associated with on heartbeat.  Thus it consists of a systole and diastole of the atria plus systole and diastole of the ventricles
  7. atrial systole
    the atria are contracting the same time the ventricles are relaxing
  8. ventricular systole
    the ventricles are contracting the same time the atria are relaxing
  9. isovolumetric contraction
    during this interval cardiac muscle fibers are contracting exerting force but are not yet shortened.  Both semilunar valves and AV valves are closed
  10. ventricular ejection
    the period when the SL valves are open
  11. end-systolic volume (ESV)
    the volume remaining in each ventricle at the end of systole
  12. stroke volume
    the volume ejected per beat from each ventricle, equals end-diastolic volume minus end systolic volume
  13. relaxation period
    the atria and ventricles are both relaxed.
  14. ventricular diastole
    caused by ventricular repolarization as the ventricles relax pressure within the chambers falls
  15. isovolumetric relaxation
    after the sl valves close there is a brief interval when ventricular blood volume does not change because all four valves are closed.
  16. ventricular filling
    as the ventricles continue to relax.  The pressure falls quickly. When ventricular pressure falls below atrial pressure, the av valves open and this begins
  17. heart sounds
    during each cardiac cycle there are four of these. but in a normal heart only the first and second heart sounds are loud enough to hear
  18. lubb
    the first sound.  Is louder and a bit longer than the second sound.  it is caused by blood turbulence associated with closure of the AV valves soon after ventricular systole begins
  19. dupp
    the second heart sound which is shorter and not as loud as the first.  it is caused by blood turbulence associated with closure of the SL valves at the beginning of the ventricular diastole
  20. heart murmur
    is an abnormal sound consisting of a clicking rushing or gurgling sound that either is hear before, between or after the normal heart sounds or may mask the normal heart sounds.
Card Set
The Heart part 3
The Heart part 3