<prompt> A traveling nerve impulse does not depolarize the area immediately behind it, because:It is hyperpolarisedIt is refractoryIt is not self-propagatingThe conduction is always ohodromic  <response>: When an AP is initiated at a point, the point goes into refractoriness when the Na entered through that point has excited the adjacent 2nd point. so it will travel in single direction Hyperpolarization event is after the refractory period. 