<prompt> In conduction system of hea the maximum velocity of conduction is seen in?SA nodeAV nodeBundle of HISPurkinje fibers  <response>: Purkinje fibers are characterized by action potentials with a low resting membrane potential -- 90 mV, a rapid maximum upstroke velocity 500 to 700 Vs, and, therefore, a rapid conduction velocity. Purkinjes fibres have many gap junctions which allows the rapid flow of current and hence the conduction velocity is maximum in Purkinjes fibres. This rapid conduction allows simultaneous contraction of both the ventricles. Ref: Moss and Adams Hea Disease in Infants, Children, and Adolescents ... By Ahur J. Moss, Hugh D. Allen, M.D., 2007, Page 24, Table 1.2; Guytons physiology, 22nd edition, Page 105. 