In which area does the pacemaker function during ventricular rhythms?

The pacemaker function during ventricular rhythms occurs in the ventricles. This is because, when normal conduction pathways are disrupted, such as in cases of junctional or ventricular rhythms, the ventricles themselves can assume the role of the pacemaker. In these situations, specialized myocardial cells within the ventricles generate electrical impulses to maintain a heartbeat, typically at a slower rate than the atria or when normal pacemakers like the sinoatrial (SA) node or atrioventricular (AV) node fail to function properly.

The other structures mentioned have specific roles in normal conduction. The sinoatrial node is the heart's primary pacemaker located in the atria, controlling the overall heart rhythm under normal circumstances. The AV node serves as a relay point between the atria and ventricles but does not generate impulses in the context of ventricular rhythms. Therefore, when discussing pacemaker function specifically during ventricular rhythms, the focus is rightly on the ventricles themselves, highlighting their ability to manage rhythms in the absence of higher pacemaker activity.