The Conducting System
IntroductionThe heart's conducting system consists of the sinoatrial node (SA node), atrioventicular node (AV node), the bundle of His, the bundle branches and the Purkinje fibers.
The electrical impulse that causes rhythmic contraction of heart muscles arises in the SA node which is the intrinsic pacemaker of the heart. From the SA node, the impulse spreads over the atrial muscles causing atrial contraction. The impulse is also conducted to the atrioventicular (AV) node.
From the AV node the electrical impulse is conducted to ventricular muscles via the bundle of His, the bundle branches and the Purkinje fibers. The bundle branches and the Purkinje fibers are collectively called the ventricular conduction system.
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