part of part of in left side of conducting system of heart bundle of His His-Purkinje system left bundle branch left bundle branch left bundle branch of bundle of His left bundle of atrioventricular bundle The left branch of the atrioventricular bundle that separates at the bundle of His, descends the septal wall of the left ventricle and connects to the terminal Purkinje fiber[MP]. UBERON:0005986 SCTID:277690001 left branch of atrioventricular bundle FMA:9487 crus sinistrum (fasciculi atrioventricularis) left crus of atrioventricular bundle left posterior bundle galen:LeftBundleBranch left posterior branch conducting tissue of heart lateral structure cardiac muscle tissue of ventricle