the bundle of modified cardiac muscle fibers that begins at the atrioventricular node as the trunk of the atrioventricular bundle and passes through the right atrioventricular fibrous ring to the membranous part of the interventricular septum where the trunk divides into two branches, the right crus of the atrioventricular bundle and the left crus of the atrioventricular bundle; the two crura ramify in the subendocardium of their respective ventricles. Syn: fasciculus atrioventricularis [NA], atrioventricular band, Gaskell’s bridge, His‘ band, His‘ bundle, bundle of His, Keith’s bundle, Kent’s bundle(1), Kent-His bundle, ventriculonector.