[Campbell Biology P.977] Which of the following accurately describes the primary function of... | Practice Question

Which of the following accurately describes the primary function of the atrioventricular AV node in the heart's electrical conduction system?

  • A: It acts as the primary pacemaker, setting the rate and timing for all cardiac muscle cells.
  • B: It delays the electrical impulses for approximately 0.1 second, allowing the atria to empty completely before the ventricles contract.
  • C: It directly conducts signals throughout the ventricular walls via Purkinje fibers.
  • D: It receives signals from the sympathetic division to accelerate the heart rate.

Explanation

The text explicitly states that the atrioventricular AV node is a relay point where "the impulses are delayed for about 0.1 second before spreading to the heart apex. This delay allows the atria to empty completely before the ventricles contract."