What is the function of the AV node?

What is the function of the AV node?

• A. To initiate the cardiac cycle
• B. To delay the signal between atria and ventricles
• C. To regulate the heart rate
• D. To conduct signals from the ventricles

Answer: (B)

The AV node, or atrioventricular node, plays a crucial role in the electrical conduction system of the heart by serving as a critical delay point between the atria and the ventricles. This delay ensures that the atria have enough time to complete their contraction and fully pump blood into the ventricles before the ventricles begin to contract. The timing is essential for effective heart function, allowing for coordinated heartbeats and optimal blood flow.

By delaying the electrical signal, the AV node prevents rapid, simultaneous contraction of the heart chambers, which could severely compromise blood circulation. The ability of the AV node to create this delay is fundamental to maintaining the proper sequence of contractions within the heart, thereby contributing to the overall efficiency of the cardiac cycle.