True statement regarding purkinje fibres: September 2009, March 2013: (A) Are myelinated fibres, (B) Have action potential about a tenth as long as those in the hea muscle, (C) Have conduction velocity of four times than that of the hea muscle, (D) All of the above
Answer is C. Ans. C: Have conduction velocity of four times than that of the hea muscle Conduction rate is 4 m/s in purkinje fibers whereas it is 1 m/s in ventricular muscles, atrial pathways and Bundle of His. SA Node and AV Node has a conduction speed of 0.05 m/s