ANATOMY

Detailed explanation-1: -The SA (sinoatrial) node generates an electrical signal that causes the upper heart chambers (atria) to contract. The signal then passes through the AV (atrioventricular) node to the lower heart chambers (ventricles), causing them to contract, or pump. The SA node is considered the pacemaker of the heart.

Detailed explanation-2: -The sinoatrial node, better known as the sinuatrial or SA node is the key structure responsible for the generation of a regular heartbeat and is therefore often referred to as the pacemaker of the heart.

Detailed explanation-3: -A pacemaker is also called a cardiac pacing device.

Detailed explanation-4: -The sinus node is the heart’s natural pacemaker. It’s a small mass of specialized cells in the top of the right atrium (upper chamber of the heart). It produces the electrical impulses that cause your heart to beat.