What is the primary function of the atrioventricular (AV) node?

The primary function of the atrioventricular (AV) node is to transmit electrical impulses from the atria to the ventricles. This is a crucial role in the heart's electrical conduction system. The AV node serves as an electrical bridge between the atria, which contract first to fill the ventricles with blood, and the ventricles, which need to contract subsequently to pump blood out of the heart.

When the electrical signal from the sinoatrial (SA) node, the heart's natural pacemaker, reaches the AV node, it causes a brief delay. This delay allows the atria time to fully contract and empty their blood into the ventricles before the ventricles themselves contract. The coordinated conduction of impulses ensures efficient blood flow and allows the heart to function effectively as a pump.

This role is vital for proper heart function and contributes to the overall rhythm and timing of the heartbeat, making the AV node an essential component of the cardiac conduction system.