Question

What do you mean by pacemaker of heart?Define by -pass surgery in humans.

Answer 1

A pacemaker: a device for stimulating the heart muscle and regulating its contractions.

Bypass surgery: Heart bypass surgery, or coronary artery bypass surgery, is used to replace damaged arteries that supply blood to your heart muscle. A surgeon uses blood vessels taken from another area of your body to repair the damaged arteries. 

Answer 2

A pacemaker is a small device that's placed in the chest or abdomen to help control abnormal heart rhythms. This device uses electrical pulses to prompt the heart to beat at a normal rate. Pacemakers are used to treat arrhythmias (ah-RITH-me-ahs). Arrhythmias are problems with the rate or rhythm of the heartbeat.