Which of These Statements Describes the AV Node

Question

Which of these statements describes the AV node
A)It is the normal pacemaker of the heart.
B)It is the only electrical connection between the atria and the ventricles.
C)It rapidly conducts the impulse from the atria to the ventricles so that they contract simultaneously.
D)It is not innervated by the vagus.

Accepted Answer

The AV node is the only electrical connection between the atria and the ventricles. It receives the electrical impulse from the SA node in the atria and delays it briefly before transmitting it to the ventricles. This delay allows the atria to fully contract before the ventricles begin to contract, ensuring efficient blood flow. However, the SA node is the normal pacemaker of the heart as it sets the rate of the heartbeat. The AV node does not rapidly conduct the impulse; rather, it delays it. Finally, the AV node is innervated by the vagus nerve, which helps to slow down the heart rate.