<prompt> The superior oblique muscle is supplied by3rd cranial nerve4th cranial nerve5th cranial nerve6th cranial nerve  <response>: Superior oblique muscle is supplied by fouh cranial nerve i.e,trochlear nerve. It supplies only the superior oblique muscle of the eyeball. Superior oblique muscle helps in depression,abduction and intoion. Note: When trochlear nerve is damaged, diplopia occur looking downwards; vision is single so long as the eye look above the horizontal plane. Ref:BDC 6th edition of no.208 