Impulse of heartbeat originates from:
1. S.A. Node
2. A. V. Node
3. Vagus Nerve
4. Cardiac Nerve
The cardiac pacemaker in a patient fails to function normally. The doctors find that an artificial pacemaker is to be grafted into him. It is likely that it will be grafted at the site of:
1. Purkinje system
2. Sinoatrial node
3. Atrioventricular node
4. Atrioventricular bundle