MEDICAL PHYSIOLOGY

Detailed explanation-1: -The sinoatrial node (SA node) is the primary pacemaker of the heart.

Detailed explanation-2: -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.

Detailed explanation-3: -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-4: -Pacemaker cells stimulate the spontaneous contraction of cardiac muscle as a functional unit, called a syncytium.