What is the rate per minute of the AV junction?

The atrioventricular (AV) junction serves as a critical gateway for electrical impulses between the atria and ventricles of the heart. In cases where the primary pacemaker, the sinoatrial (SA) node, fails or becomes ineffective, the AV junction can take over as an alternative pacemaker.

The intrinsic firing rate of the AV junction is typically between 40 and 60 beats per minute. This rate is slower than that of the SA node, which is usually between 60 and 100 beats per minute. The primary role of the AV junction as a pacemaker is not only to maintain a heart rate but also to ensure that the electrical signals are transmitted appropriately to the ventricles after slightly delaying them, allowing the atria to contract and fill the ventricles with blood before ventricular contraction.

Understanding this function is essential for recognizing how the heart manages rhythms in different situations, especially in cases of heart block or other conduction disturbances where the normal rhythm is disrupted. Thus, the correct answer indicates the typical functionality of the AV junction as a secondary pacemaker within this specific rate range.