The role of the atrioventricular node (AV node) is to __________.

• A. initiate a sinus rhythm
• B. slow down impulses so that the atria can contract to fill the adjacent ventricles with blood
• C. initiate ventricular depolarization
• D. conduct impulses to the sinoatrial node (SA node)

Answer: (B)

Verified step by step guidance

1. Understand the location and function of the atrioventricular node (AV node) in the heart's conduction system. The AV node is situated between the atria and ventricles and plays a crucial role in coordinating the timing of heart contractions.
2. Recognize that the primary function of the AV node is to delay the electrical impulses received from the sinoatrial node (SA node). This delay is essential for allowing the atria to contract and fill the ventricles with blood before the ventricles contract.
3. Differentiate between the roles of the SA node and the AV node. The SA node is responsible for initiating the sinus rhythm, which is the natural pacemaker activity of the heart, while the AV node modulates the timing of these impulses.
4. Consider the options provided in the problem. The correct function of the AV node is to slow down impulses so that the atria can contract to fill the adjacent ventricles with blood, ensuring efficient blood flow and cardiac function.
5. Reflect on the importance of the AV node's role in preventing the ventricles from contracting prematurely, which would lead to inefficient blood circulation and potential cardiac complications.