The AV node is the only anatomical connection between which portions of the heart's conduction system?

• A. Atrial and ventricular portions
• B. Left and right atria
• C. Aorta and ventricles
• D. Sinoatrial node and AV node

Answer: (A)

The AV node serves as the sole gateway between the atrial conduction system and the ventricular conduction system. impulses begin in the atrial pathways (including the SA node and internodal tracts) and travel to the AV node, which sits at the border between the atria and the interventricular septum. From there, the impulse travels through the His bundle and Purkinje network to activate the ventricles. The heart’s fibrous skeleton largely insulates atria from ventricles, so there isn’t a direct atria-to-ventricle conduction pathway other than through the AV node (and its continuation via the His-Purkinje system). Other options either remain within the atria (connections between the left and right atria) or are not part of the conduction system at all (the aorta).