In which direction does depolarization occur during ventricular depolarization?

In which direction does depolarization occur during ventricular depolarization?

• A. Outward to inward
• B. Inward to outward
• C. From base to apex
• D. From epicardium to endocardium

Answer: (A)

During ventricular depolarization, the direction of depolarization is specifically from the endocardium to the epicardium. This means that within the walls of the ventricles, the inner layers (endocardium) are activated first, leading to contraction that moves outward towards the outer layers (epicardium).

This phenomenon ensures a coordinated contraction of the heart muscle, starting from the inner chambers where blood is pumped towards the aorta and pulmonary arteries before ultimately reaching the outer layers.

The correct answer captures the essential principle of myocardial action potential propagation during depolarization, highlighting the functional efficiency of the heart's pumping mechanism. Understanding this directionality is crucial for interpreting EKG results and recognizing any abnormalities related to ventricular depolarization.