Question

which feature of the cardiac conduction system is the only electrical connection between the atria and ventricles?
a sa node
b av node
c av bundle
d bundle branches

Explanation:

To solve this, we analyze each option:

• Option A (SA node): It is the pacemaker of the heart, initiating electrical impulses in the atria, not the connection between atria and ventricles.
• Option B (AV node): The atrioventricular (AV) node is the only electrical connection between the atria and ventricles. It delays the impulse to allow atrial contraction before ventricular contraction.
• Option C (AV bundle): It conducts impulses from the AV node to the ventricles, but it is not the only connection between atria and ventricles (the AV node is the connection point).
• Option D (Bundle branches): These are part of the ventricular conduction system, carrying impulses within the ventricles, not connecting atria and ventricles.

Answer:

B. AV node