APPLIED RADIOLOGICAL ANATOMY

Detailed explanation-1: -It delays the signal by a consistent amount of time (a fraction of a second) each time. The delay ensures that your atria are empty of blood before the contraction stops.

Detailed explanation-2: -Disease of the AV node can cause either a delay or a partial or complete block in the transmission of electrical impulses from the atria to the ventricles, a condition known as heart block. A delay in conduction through the AV node is seen on the ECG as an increased PR interval.

Detailed explanation-3: -The electrical impulse then spreads to the atrioventricular (AV) node, which is another clump of specialized tissue located between the atria and the ventricles. The AV node momentarily slows down the spread of the electrical impulse, to allow the left and right atria to finish contracting.