Final answer:
The left AV node is referred to as the left bundle branch, which is part of the heart's electrical conduction system, ensuring the coordinated contractions of the heart's chambers.
Step-by-step explanation:
The left atrioventricular (AV) node is commonly referred to as the left bundle branch. It is part of the electrical conduction system of the heart which ensures synchronized contractions between the atria and the ventricles. After the AV node receives the impulse from the sinoatrial (SA) node, which is the pacemaker of the heart, there is a critical pause. This allows the atria to complete their contraction, hence efficiently pumping blood into the ventricles before the impulse is further transmitted. The electrical impulse then moves through the atrioventricular bundle (bundle of His), which divides into the left and right bundle branches. The left bundle branch is larger due to the left ventricle being more robust in comparison to the right. The electrical signal travels through these branches to the respective ventricles, coordinating their contractions. This precise conduction sequence is vital for the heart's function and efficient blood flow throughout the body.