All are actions of superior oblique except:

Ans: a (Extorsion) Ref:Khorana, 4th ed, p. 315All are actions of superior oblique except extorsion which is the primary action of the inferior obliqueAction of extraocular musclesMusclePrimary actionSecondary actionTertiary actionMRAdduction LRAbduction SRElevationIntorsionAdductionIRDepressionExtorsionAdductionSOIntorsionDepressionAbduction10ExtorsionElevationAbduction Some useful mnemonics:All superiors are intorters. So inferiors are extortersAll recti are adductors. So obliques are abductorsRegarding nerve supply: Remaining all including levator palpabrae superioris by 3rd nerve.