What is the definition of the AV Junction?

The correct definition of the AV junction is the point where electrical impulses travel from the atria to the bundle of His. This area plays a crucial role in the conduction system of the heart. Specifically, the atrioventricular (AV) junction consists of specialized tissue located between the atria and ventricles, which includes the AV node and the surrounding tissues.

During a normal cardiac cycle, after the electrical impulses are generated in the sinoatrial (SA) node, they travel through the atria and reach the AV junction. Here, the signals are briefly delayed, allowing the atria to finish contracting and emptying blood into the ventricles before the ventricles contract. This timing is essential for maintaining effective heart function and ensuring that blood is pumped efficiently throughout the body.

The other choices do not accurately describe the function or location of the AV junction. The main pacemaker of the heart refers to the SA node, and the Purkinje fibers are the terminal point of conduction within the ventricles, continuing from the bundle of His, not emerging from the AV junction. The area responsible for regulating blood pressure primarily involves the vascular system and is influenced by various factors, but it is not the AV junction.