University of Central Florida (UCF) PCB3703C Human Physiology Lab Practice Exam 2

Ventricular depolarization is the physiological process that precedes ventricular systole in the heart cycle. This process is initiated by the electrical signal generated by the sinoatrial (SA) node, which travels through the atria causing atrial depolarization and contraction. Following atrial contraction, the electrical impulse reaches the atrioventricular (AV) node, then propagates through the bundle of His and Purkinje fibers into the ventricles. The depolarization of the ventricular myocardium triggers the ventricles to contract, which is known as ventricular systole.

This sequence is critical as the timing of these electrical events ensures that the heart functions efficiently, allowing for proper blood flow from the atria to the ventricles and then out to the lungs and the rest of the body during each heartbeat. Understanding this progression highlights the interconnectedness of electrical activity and mechanical function in the cardiac cycle.