The atrio- ventricular node is a mass of tissue seen in the lower left corner of the right atrium close to the antrio- ventricular septum and the atrio ventricular bundle is the continuation of AVN which passes through the atrio ventricular septa and it divides immediately into right and left bundle. Both AVN and AN have the ability to generate action potential and their main function is to get excited by the action potential initiated by the Sino- atrial node and conduct the stimulus to the remaining part of the heart through which they branch thus helping in the rhythmic contraction and relaxation of the heart.