Anatomy · Thorax

Conducting system of heart and its anatomical basis

4 min read

  • Conducting system of the heart: network of specialized cardiac muscle fibres (not nervous tissue) that initiates and conducts the cardiac impulse.

Components of the Conducting System

Organization

  • Five components, in sequence: SA node, AV node, AV bundle (of His), right and left bundle branches, Purkinje fibres.
  • SA node (node of Keith-Flack): pacemaker of the heart; generates impulses at about 70/min, initiating each heartbeat.
  • AV node (node of Tawara): picks up the atrial impulse and conducts it to the ventricles through the AV bundle; generates impulses at about 60/min.
  • AV bundle (of His): the fibrous skeleton of the heart separates atrial from ventricular muscle, so the AV bundle is the only pathway conducting impulses from atria to ventricles.
  • Right and left bundle branches descend either side of the interventricular septum and end as Purkinje fibres, spreading subendocardially over the septum and ventricular walls.