Specialized conduction pathways between AVN and ventricular muscle ensure what?

• A. Rapid activation of ventricles
• B. Slower activation of ventricles
• C. No coupling
• D. Atrial-only activation

Answer: (A)

Specialized conduction pathways from the AV node into the ventricular muscle are built for rapid spread of the impulse. After the AV node provides a necessary delay to allow ventricular filling, the impulse travels through the His-Purkinje system, which conducts much faster than ordinary ventricular myocardium. This fast conduction makes the activation of the ventricles nearly simultaneous, ensuring coordinated and efficient contraction. If activation were slower, the ventricles would not depolarize as synchronously, reducing the efficiency of pumping. Therefore, these pathways ensure rapid activation of the ventricles.