Conduction system of the heart (English)

The conduction system of the heart is formed by specialized cardiac muscle fibers that are responsible for the initiation and conduction of cardiac impulses. The conduction system is composed of five components: the sinuatrial (SA) node, atrioventricular (AV) node, AV bundle, right and left branches of the atrioventricular bundles (of His) and the subendocardiac fibers (Purkinje fibers). The SA node is the pacemaker of the heart and is located superior to the sulcus terminalis of the right atrium. The AV node is also located in the right atrium. It picks up and propagates action potentials produced by the sinuatrial node, however is also capable of producing its own action potentials. The atrioventricular bundle (of His) is made up of specialized cardiac muscle fibers that extend through the interatrial septum as far as the apex of the heart. These fibers then divide into subendocardiac (Purkinje) fibers that extend into the myocardium of the ventricles.