Final answer:
The bundle of His splits into the left and right bundle branches which carry the electrical impulse to the ventricles. These branches also lead to the Purkinje fibers and contribute to the contraction of the ventricles during the heart's pumping cycle.
Step-by-step explanation:
The bundle of His splits into the left and right bundle branches that carry an electrical impulse to the ventricles. Arising from the AV node, the atrioventricular bundle, or bundle of His, passes through the interventricular septum, and then divides into left and right branches. These bundle branches are tasked with supplying the left and right ventricles respectively. The left bundle branch is larger due to the greater size of the left ventricle. These branches lead to the Purkinje fibers, which then conduct the impulses throughout the ventricular myocardium, causing the ventricles to contract. Moreover, the right bundle branch extends to the right papillary muscle via the moderator band, timing the contraction of papillary muscles with the ventricles.