Interventricular septum

This section of the heart includes the muscular and membranous portions of the interventricular septum and the right atrioventricular valve.  40x

The interventricular septum is formed by a membranous portion (septum membranaceum) of dense connective tissue and a muscular portion composed of cardiac muscle.

The interventricular septum is formed by a membranous portion (septum membranaceum) of dense connective tissue and a muscular portion composed of cardiac muscle.

The interventricular septum is formed by a membranous portion (septum membranaceum) of dense connective tissue and a muscular portion composed of cardiac muscle.

The atrioventricular valve separates the right atrium from the right ventricle.

The atrioventricular (AV) bundle, part of the conducting system, is in septum membranaceum just above the muscular part of the septum.  Right and left bundle branches begin in the AV bundle and conduct impulses to the right and left ventricles, respectively.  Fibers in these three subdivisions are modified cardiac muscle fibers that are usually smaller than normal cardiac fibers.

The atrioventricular (AV) bundle, part of the conducting system, is in septum membranaceum just above the muscular part of the septum.  Right and left bundle branches begin in the AV bundle and conduct impulses to the right and left ventricles, respectively.  Fibers in these three subdivisions are modified cardiac muscle fibers that are usually smaller than normal cardiac fibers.

The atrioventricular (AV) bundle, part of the conducting system, is in septum membranaceum just above the muscular part of the septum.  Right and left bundle branches begin in the AV bundle and conduct impulses to the right and left ventricles, respectively.  Fibers in these three subdivisions are modified cardiac muscle fibers that are usually smaller than normal cardiac fibers.

This area is shown at higher magnification in the next image.