Emergency Medical Technician (EMT) Intermediate Practice Exam

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

1. To initiate the heart's electrical impulse

2. To slow conduction from the atria to the ventricles to allow for ventricular filling

3. To increase heart rate during exercise

4. To connect the right atrium to the right ventricle

The correct answer is: To slow conduction from the atria to the ventricles to allow for ventricular filling

The primary function of the atrioventricular (AV) node is to slow conduction from the atria to the ventricles, which allows for adequate ventricular filling. This process is crucial because it ensures that the ventricles have enough time to fill with blood before they contract and pump it out to the lungs and the rest of the body. The AV node acts as a critical relay point in the heart's electrical conduction system. When the electrical impulse generated by the sinoatrial (SA) node reaches the AV node, there is a brief delay before the impulse is passed on to the ventricles. This delay is integral in coordinating the timing of the heart's contractions, enabling effective blood flow and maintaining proper cardiac function. In contrast, other options describe different aspects of heart physiology or address functions that are not related to the AV node. The initiation of the heart's electrical impulse is the role of the SA node. Increasing the heart rate during exercise is influenced by the autonomic nervous system rather than a specific function of the AV node. Lastly, the AV node does not directly connect the right atrium to the right ventricle; that connection is through the valves and the electrical conduction system ensures communication between these chambers. Understanding the specific