What is the significance of the atrioventricular (AV) node?

The atrioventricular (AV) node plays a crucial role in the cardiac conduction system by conducting electrical impulses from the atria to the ventricles. One of its primary functions is to briefly delay the impulse after it is received from the sinoatrial (SA) node, which allows for the atria to contract fully and pump blood into the ventricles before the ventricles contract. This delay is essential for ensuring proper filling of the ventricles, which is vital for efficient heart function and maintaining an adequate cardiac output.

By allowing this timely delay, the AV node ensures that the heart beats in a coordinated manner, optimizing blood flow throughout the body. If impulses were to travel directly from the atria to the ventricles without this critical pause, the ventricles could contract too early, leading to ineffective pumping and inadequate blood circulation. Thus, the role of the AV node is not only about conducting electrical signals but also about coordinating the timing of heart contractions to support overall cardiovascular health.