What structure divides into the right and left bundle branches?

The structure that divides into the right and left bundle branches is the atrioventricular bundle, also known as the Bundle of His. It serves a crucial role in the heart’s conduction system by conducting electrical impulses from the atrioventricular node down into the interventricular septum. Once it reaches the septum, the bundle divides into two branches: the right bundle branch, which sends impulses to the right ventricle, and the left bundle branch, which supplies the left ventricle. This division ensures that both ventricles can contract simultaneously and effectively pump blood throughout the body.

Understanding the function of the atrioventricular bundle illustrates its importance in coordinating the heartbeat, making it a critical component in the heart's electrical conduction system. The other options do not play a direct role in dividing into the bundle branches; for instance, Purkinje fibers are part of the conduction system that distributes impulses to the ventricular muscle to facilitate contraction, but are not responsible for the division of the bundle branches. The sinoatrial node serves as the natural pacemaker of the heart and initiates the heartbeat, and the cardiac septum is a structural wall dividing the left and right sides of the heart, but it does not function in generating or