Blood is pumped by the heart by rhythmic contractions and relaxation (heart beat) of the auricles and ventricles in a definite order.
The conducting system brings about the rhythmic and automatic working of the heart (i.e. contraction and relaxation of the heart) through the transmission of impulses generated within specialised cardiac muscles and its channels, thereby accomplishing continuous circulation (or pumping) of blood through the heart.
The impulses for initiation of heart beat starts in the SAN (Sino-atrial node) or Pacemaker of the heart and is transmitted to the AV node (Atrioventricular node) through 3 special tracts or pathways (composed of specialised cardiac muscle fibres) called internodal pathways. From here the stimulus is carried by a single tract of specialised muscle called the “Bundle of His” in the beginning and diverted to the left and right side of the heart by its branches, (i.e. left and right branches).
These branches later rebranch profusely into Purkinje fibres. The Purkinje’s fibres transmit the Impulses received from the branches of Bundle of His to all the parts of the Ventricles bringing about simultaneous contraction of Ventricle pumping blood from right ventricle into lungs through pulmonary artery and pumping blood from left ventricle into aorta to various parts of the body through its branches. In this way impulses are transmitted through the conducting system ensuring systematic working of heart and blood supply.
