What is the role of the AV node?

What is the role of the AV node?

• A. To relay electrical signals from the atria to the ventricles.
• B. To initiate the heartbeat.
• C. To contract the ventricles directly.
• D. To store electrical energy.

Answer: (A)

The AV node mainly serves to relay the electrical signal from the atria to the ventricles, plus it adds a short delay to the transmission. This delay is crucial because it gives the atria time to finish contracting and actively fill the ventricles before they begin to contract. Without this delay, the timing between atrial and ventricular contractions could be off, reducing the heart’s pumping efficiency. The AV node sits between the atrial myocardium and the ventricles, so it isn’t responsible for initiating the heartbeat—that role belongs to the SA node. It also doesn’t cause the ventricles to contract directly or store electrical energy; its job is to conduct and time the impulse as it moves into the His-Purkinje system to trigger ventricular contraction.

The AV node mainly serves to relay the electrical signal from the atria to the ventricles, plus it adds a short delay to the transmission. This delay is crucial because it gives the atria time to finish contracting and actively fill the ventricles before they begin to contract. Without this delay, the timing between atrial and ventricular contractions could be off, reducing the heart’s pumping efficiency.

The AV node sits between the atrial myocardium and the ventricles, so it isn’t responsible for initiating the heartbeat—that role belongs to the SA node. It also doesn’t cause the ventricles to contract directly or store electrical energy; its job is to conduct and time the impulse as it moves into the His-Purkinje system to trigger ventricular contraction.