bell um . ▁ ▁It ▁ar ises ▁from ▁the ▁bas ilar ▁ar tery ▁on ▁each ▁side ▁at ▁the ▁level ▁of ▁the ▁j unction ▁between ▁the ▁med ulla ▁ob long ata ▁and ▁the ▁p ons ▁in ▁the ▁bra inst em . ▁It ▁has ▁a ▁variable ▁course , ▁passing ▁back ward ▁to ▁be ▁distributed ▁to ▁the ▁anterior ▁part ▁of ▁the ▁unders ur face ▁of ▁the ▁c ere bell um , ▁an ast om osing ▁with ▁ ▁both ▁the ▁posterior ▁inferior ▁c ere bell ar ▁( PI CA ) ▁branch ▁of ▁the ▁verte br al ▁ar tery ▁and ▁the ▁superior ▁c ere bell ar ▁ar tery . ▁ ▁It ▁also ▁gives ▁off ▁the ▁internal ▁aud itory ▁or ▁lab yr inth ine ▁ar tery ▁in ▁most ▁cases ; ▁however , ▁the ▁lab yr inth ine ▁ar tery ▁can ▁less ▁commonly ▁emer ge ▁as ▁a ▁branch ▁of ▁the ▁bas ilar ▁ar tery . ▁ ▁The ▁amount ▁of ▁t issue ▁supplied ▁by ▁the ▁A IC A ▁is ▁variable , ▁depending ▁upon ▁whether ▁the ▁P IC A ▁is ▁more ▁or ▁less ▁dominant , ▁but ▁usually ▁includes ▁the ▁an tero in fer ior ▁surface ▁of ▁the ▁c ere bell um , ▁the ▁flo cc ulus , ▁middle ▁c ere bell ar ▁ped un cle ▁and ▁infer ol ater al ▁portion ▁of ▁the ▁p ons . ▁ ▁C lin ical ▁significance ▁Occ l usion ▁of ▁A IC A ▁is ▁considered ▁rare , ▁but ▁generally ▁results ▁in ▁a ▁later al ▁pont ine ▁synd rome , ▁also ▁known ▁as ▁A IC A ▁synd rome