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Cardiovascular Physiology
The Cardiac Cycle
1. Identify the 3 components to diastole.
The components are:

  • The rapid filling phase: when the pressure in the ventricles falls below that of the atria.
  • Diastasis: the middle of diastole when there is minimal flow between the atria and ventricle due to relatively equal pressures.
  • Atrial contraction: the final filling of the ventricles occurs because of atrial contraction pushing the last of the preload into the ventricle.
  • 2. Wiggers Diagram:
    Wiggers Diagram shows what is occurring in the atria and ventricles (with respect to volume and pressure) during each phase.

    Identify the events known as isovolumetric contraction and relaxation in terms of:

  • When do they occur
  • What is happening to pressure and volume during these periods
  • What is occurring with respect to the A-V and semilunar valves during these periods
  • The pressure-volume loop - be able to draw and label it.