Bundle branches are specialized pathways in the heart's electrical conduction system. They are part of the atrioventricular bundle, also known as the Bundle of His, which splits into two main branches: the left bundle branch and the right bundle branch. These branches help transmit electrical signals from the atrioventricular node to the ventricles, ensuring coordinated heart contractions. The left bundle branch further divides into two fascicles, known as the anterior and posterior fascicles, which supply the left ventricle. Proper functioning of the bundle branches is crucial for maintaining a regular heartbeat. Any blockages or dysfunctions in these branches can lead to bundle branch block, affecting heart efficiency.