What does the AV node do?

The atrioventricular (AV) node plays a crucial role in the cardiac conduction system by relaying electrical impulses from the atria to the ventricles. This node serves as a gateway that allows the signal, which triggers heart contractions, to pass from the atrial muscles to the ventricular muscles. After the atria contract and push blood into the ventricles, the AV node ensures that there is a slight delay before the ventricles contract, allowing them to fill properly with blood. This coordinated timing is essential for effective heart function.

The AV node does not initiate heart contractions; that function is primarily performed by the sinoatrial (SA) node, which acts as the natural pacemaker of the heart. While it contributes to regulating heart rhythm, its main and specific role is transmitting impulses rather than regulating the overall rhythm of the heart. Additionally, the AV node does not stimulate respiration, which is governed by a different set of neural pathways and centers in the brain.