Question

What are nodal tissues distributed in heart?Describe how they are distributed in heart.

Answer 1

Nodal tissues are a small mass of specialized cardiac muscle fibers, located in the wall of the right atrium of the heart, that receives electrical impulses from the sinoatrial node and directs them to the conduction system in the walls of the ventricles.

SA Node: A patch of this tissue is present in the right upper corner of the right atrium called the sino-atrialnode (SAN).AV Node: Another mass of this tissue is seen in the lower left corner of the right atrium close to the atrio-ventricular septum called the atrio-ventricular node (AVN).Bundle of His: A bundle of nodal fibres, atrioventricular bundle (AV bundle) continues from the AVN whichpasses through the atrio-ventricular septa to emerge on the top of the interventricular septum andimmediately divides into a right and left bundle. These branches give rise to minute fibres throughout theventricular musculature of the respective sides and are called purkinje fibres. These fibres alongwith rightand left bundles are known as bundle of HIS.