MICROANATOMY

Detailed explanation-1: -The heart’s intrinsic pacemaker, the sinoatrial node (SAN), generates spontaneous action potentials (AP) through a system of coupled oscillators whose common output initiates each normal heartbeat.

Detailed explanation-2: -Action potentials generated cyclically by the SA node spread around the right atrium and left atrium, causing them to contract, forcing their contents into the ventricles. This wave of depolarisation then reaches the atrioventricular node (AV node) which is the entry point for action potentials to the ventricles.

Detailed explanation-3: -The delay ensures that your atria are empty of blood before the contraction stops. The atria are the heart’s upper chambers. They receive blood from your body and empty it into the ventricles.

Detailed explanation-4: -Clinical Significance. Without this brief delay in the electrical impulse, the atria would not be able to finish beating-allowing the ventricles to completely fill with blood-before the ventricles themselves begin to beat.