PATHOLOGY

Detailed explanation-1: -In 1893, Wilhelm His Jr. discovered the physical link that electrically bridges the atria and ventricles of the heart. [1] This specialized muscle bundle connecting the atrial and ventricular chambers of the heart is now known as the bundle of His.

Detailed explanation-2: -a bundle of specialized muscle fibers regulating the heartbeat by conducting impulses from the right atrium to the ventricles.

Detailed explanation-3: -The atrioventricular node (also known as the AV node) is a collection of specialized cardiac muscle cells, which are bundled together to form a node within the wall of the interatrial septum.