Final answer:
AV nodal cells are special heart cells responsible for delaying electrical impulses, ensuring proper timing for heart contractions, and can transmit impulses at a rate of up to 220 per minute under extreme stimulation by the SA node.
Step-by-step explanation:
The Atrioventricular (AV) nodal cells are specialized myocardial conductive cells located in the inferior portion of the right atrium within the atrioventricular septum. These cells play a critical role in the heart's electrical conduction system. The conduction of impulses through the AV node is characterized by a critical pause, allowing the atria to complete contraction and pump blood into the ventricles before the ventricles themselves contract. The smaller diameter of AV nodal cells and the less efficient conduction between them slows the impulse, taking approximately 100 ms to pass through the node. Under extreme stimulation by the Sinoatrial (SA) node, the AV node can transmit impulses at a maximum rate of 220 per minute, which is the typical maximum heart rate for a healthy young individual.