The camera angle has been adjusted to provide a cross-sectional view of the interventricular septum (19). This septum has been retracted slightly away from the left ventricle and has been cut in such a way that the course of the atrioventricular bundle (6) can be traced from its origin in the A-V node (5) to its division into right and left branches (17, 18) at the junction of the membranous and muscular parts of the interventricular septum. The parts of the conduction system have been colored white to provide better photographic contrast.
Superior vena cava
Cut edge of wall of right atrium (note sinusoidal spaces filled with latex and continuous with cavity of atrium)
Fossa ovalis
Border of fossa ovalis
Atrioventricular node (colored white)
Trunk of atrioventricular bundle (colored white)
Coronary sinus
Septal (medial) cusp of tricuspid valve
Posterior cusp tricuspid valve
Myocardium of right ventricle
Right ventricle
Pulmonary trunk
Left auricle
Left coronary artery
Aortic valve (left semilunar cusp)
Membranous part interventricular septum (partially resected to display A-V bundle)
Left crus atrioventricular bundle (colored white)
Right crus atrioventricular bundle (colored white)