<prompt> Superior oblique muscle is supplied by: March 2005Third cranial nerveFouh cranial nerveFifth cranial nerveSixth cranial nerve  <response>: Ans. B: Fouh cranial nerveEach extraocular muscle is innervated by a specific cranial nerve:Medial rectus MR -- cranial nerve III OculomotorLateral rectus LR -- cranial nerve VI AbducensSuperior rectus SR -- cranial nerve III OculomotorInferior rectus IR -- cranial nerve III OculomotorSuperior oblique SO--cranial nerve IV TrochlearInferior oblique I0 --cranial nerve III Oculomotor The following can be used to remember the cranial nerve innervations of the six extraocular muscles:LR6 SO43.That is, the lateral rectus LR is innervated by C.N. 6, the superior oblique SO is innervated by C.N. 4, and the four remaining muscles MR, SR, IR, and RD are innervated by C.N. 3. 