CVS Practice Test

The correct answer is the internodal pathways. These pathways are specialized conductive tissues that facilitate the transmission of electrical impulses from the sinoatrial (SA) node, which is located in the right atrium, to the atrioventricular (AV) node. As the heart's natural pacemaker, the SA node generates the electrical impulses, which then travel through the internodal pathways to ensure timely and coordinated contraction of the heart.

The internodal pathways consist of three main tracts: the anterior internodal pathway, the middle internodal pathway, and the posterior internodal pathway. These pathways play a crucial role in ensuring that the electrical signals reach the AV node efficiently, allowing for proper timing between atrial and ventricular contractions.

In contrast, bundle branches are part of the conduction system that carries impulses through the ventricles after they pass through the AV node, while myocardial pathways refer more generally to the muscle fibers of the heart responsible for contraction and do not specifically facilitate the conduction of impulses. Coronary arteries are blood vessels that supply blood to the heart muscle; they are not involved in the conduction of electrical impulses. Thus, the role of internodal pathways is vital in the conduction system of the heart.