(a) systole Isovolumetric ventricular contraction Ventricular ejectio Systole: ventricles contracting Aortic and (b) Diastole Copyrighte~@ Companies, Ine.Permission required tor reproduction or dsplay. lumntric ventricutar retaration Bood flows into ventricles Atrial contraction reared rElaxed Diastole: ventricles relaxed Open alves Cansed closedSystole: ventricles contracting Diastole: ventricles relaxed