Cardiac conducting system of Gallus domesticus with special reference to the atrial bundles.

Gross anatomy and histology of the cardiac conducting system of Gallus domesticus has been studied. Detailed histology of the atrium revealed for the first time, in the avian heart, the presence of three atrial bundles which communicate between the sinuatrial node and the atrioventricular node. Purkinje fibres in the subendocardium of the right atrium are observed. An atrioventricular segment comprising of the posterior end of the interatrial septum and the atrioventricular nodal region has been reported in which the three atrial bundles converge. The role of the atrial bundles in the cardiac contraction has been discussed.