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

The atrioventricular (AV) node plays a crucial role in the heart's electrical conduction system by serving as a critical delay point for the electrical impulses that travel from the atria to the ventricles. When the SA node, which is located in the right atrium, generates an electrical impulse, it propagates through the atria, causing them to contract and push blood into the ventricles. The AV node then intervenes by delaying this impulse before it reaches the ventricles.

This delay is vital because it allows sufficient time for the ventricles to fill with blood from the atria before they contract. The timing is essential for maintaining effective heart function and ensuring efficient blood flow throughout the body. If the AV node did not provide this delay, the ventricles might contract too early, leading to inadequate filling and reduced cardiac output.

In contrast, the other options do not accurately describe the function of the AV node: initiating heart contractions is primarily the role of the SA node, supplying blood to the heart muscle is done by coronary arteries, and while there are mechanisms for heart rate regulation (such as autonomic nervous system influences), the AV node itself does not autonomously regulate heart rate. Its primary function relates specifically to managing the conduction of