A cut that removes the ventral walls of the ventricular and atrial chambers illustrates the muscular interventricular septum. The opening between the two ventricles is later closed by the membranous interventricular septum.

                     Species: Mouse 
                     Day Gestation: 12 
             Approx. Human Age: 6 weeks 
                                   View: Ventral
               Ventricular Septation
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