Certified Cardiovascular Technician Practice Exam

What is the primary function of the AV node in the heart?

1. To initiate the heartbeat

2. To conduct impulses to the ventricles

3. To regulate heart rate

4. To maintain blood pressure

The correct answer is: To conduct impulses to the ventricles

The primary function of the AV node, or atrioventricular node, is to conduct impulses to the ventricles. The AV node serves as a critical relay point in the heart’s electrical conduction system. After the sinus node (SA node) initiates an electrical impulse that triggers the heartbeat, this impulse travels through the atria, causing them to contract. The AV node then receives this impulse and momentarily delays it before transmitting it to the ventricles via the bundle of His. This delay is vital as it allows for the atria to fully empty blood into the ventricles before they contract. This synchronized contraction is crucial for effective blood circulation throughout the body. In contrast to this primary function, the initiation of the heartbeat is performed by the SA node, while regulation of heart rate is influenced by various factors including autonomic nervous system inputs and hormonal control. The maintenance of blood pressure involves complex interactions involving the cardiovascular system but is not the role of the AV node. Thus, the role of conducting impulses to the ventricles remains the central function of the AV node in maintaining the coordinated and efficient pumping action of the heart.