Bundle of His or A.V. bundle was discovered by His. It arises from A.V. node and descends in the interventricular septum and bifurcates into two branches innervating the wall of right and left ventricle respectively. The mybcardium of atria and ventricles are discontinuous and this bundle is the only muscular contraction between the two. It is concerned with the conduction of impulse from atria to the tip of ventricle but can also generate impulse at the rate of 35-40 per minute.