The cardiac pacemaker in a patient fails to function normally. The doctors find that an artificial pacemaker is to be grafted in him. It is likely that it will be grafted at the site of

Explanation

(c) : SA (sinoatrial) node is a specialized bundle of neurons located in the upper part of the right atrium of the heart. SA node is the natural cardiac pacemaker from which the heartbeat originates. If this system is damaged, it may send non­coordinated impulses to the heart chambers resulting in symptoms like irregular heart rate, tiredness, dizziness, and loss of consciousness. As the pacemaker cells create this rhythmical impulse therefore an artificial pacemaker is implanted at the site of the SA node to mimic the actions of the node and conducting system and helps to regulate heartbeat.