CVS Practice Test 2025 – Complete Exam Preparation

The annulus fibrosus is primarily a dense connective tissue structure that surrounds the heart valves, providing support and acting as an electrical insulator between the atria and ventricles. Its role is crucial in maintaining the separation of electrical impulses in the heart, preventing them from passing directly from the atria to the ventricles. The annulus fibrosus is indeed electrically inert, meaning it does not conduct electrical impulses.

By being electrically inert, the annulus fibrosus ensures that the electrical signals that initiate heart contractions must travel through specialized conduction pathways, such as the atrioventricular (AV) node and the bundle of His, providing structured timing to the contraction of the heart's chambers. This is important for the effective pumping action of the heart, as it allows for coordination between the atria and ventricles.

The other options suggest that the annulus fibrosus does have some capacity for electrical conduction which is not accurate. It does not conduct impulses at any time during the cardiac cycle, whether during systole or diastole. Therefore, the assertion that the annulus fibrosus is electrically inert is correct.