▁is ▁not ▁hydro ly zed ▁by ▁ac et yl ch olin ester ase . ▁By ▁maintain ing ▁the ▁memb rane ▁potential ▁above ▁threshold , ▁it ▁does ▁not ▁allow ▁the ▁mus cle ▁cell ▁to ▁rep olar ize . ▁When ▁ac et yl ch oline ▁bind s ▁to ▁an ▁already ▁dep olar ized ▁re ceptor , ▁it ▁cannot ▁cause ▁further ▁dep olar ization . ▁ ▁Cal ci um ▁is ▁removed ▁from ▁the ▁mus cle ▁cell ▁cy top las m ▁independent ▁of ▁rep olar ization ▁( dep olar ization ▁signal ing ▁and ▁mus cle ▁contra ction ▁are ▁independent ▁processes ). ▁As ▁the ▁calci um ▁is ▁taken ▁up ▁by ▁the ▁s arc op las mic ▁ret icul um , ▁the ▁mus cle ▁rela xes . ▁This ▁explains ▁mus cle ▁fla cc id ity ▁rather ▁than ▁t et any ▁following ▁fasc ic ulations . ▁ ▁The ▁results ▁are ▁memb rane ▁dep olar ization ▁and ▁trans ient ▁fasc ic ulations , ▁followed ▁by ▁par al ysis . ▁ ▁Ph ase ▁ 2 ▁block ▁ ▁While ▁this ▁phase ▁is ▁not ▁ab normal ▁and ▁is ▁a ▁part ▁of ▁its ▁mechanism ▁of ▁action , ▁it ▁is ▁und es irable ▁during ▁surg ery , ▁due ▁to ▁the ▁in ability ▁to ▁dep olar ize ▁the ▁cell ▁again . ▁O ften , ▁patients ▁must ▁be ▁on ▁a ▁vent il ator ▁for ▁hours ▁if ▁Ph ase ▁ 2 ▁block ▁occurs . ▁It ▁is ▁caused ▁by ▁the ▁blood ▁concentration ▁of ▁su x am eth on ium ▁exceed ing ▁the ▁th era pe ut ic ▁window . ▁Des