ANATOMY

Detailed explanation-1: -The sinus node continuously generates electrical impulses, thereby setting the normal rhythm and rate in a healthy heart. Hence, the SA node is referred to as the natural pacemaker of the heart.

Detailed explanation-2: -The sinus node is sometimes called the heart’s “natural pacemaker.” Each time the sinus node generates a new electrical impulse; that impulse spreads out through the heart’s upper chambers, called the right atrium and the left atrium (figure 2).

Detailed explanation-3: -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-4: -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-5: -Both nodes are capable of producing their own impulses. Though under normal conditions, when both are functional, SAN leads and AVN follows. That is, SAN activity determines the rate of heart beat. Hence it can be referred to as pace setter for the heart.