Cranial Nerve IV:Trochlear n. General somatic efferent (motor) Come from the nucleus of trochlear N.in the midbrain (The only nerve which attached to the dorsal aspect of the brain stem) Pass through superior orbital fissure Innervate the superior oblique M.(move the eye ball medially and downward Damage it may cause diplopia when try to reading or walking down stairs Come from the nucleus of trochlear N. in the midbrain (The only nerve which attached to the dorsal aspect of the brain stem)  Pass through superior orbital fissure  Innervate the superior oblique M. (move the eye ball medially and downward )  Damage it may cause diplopia when try to reading or walking down stairs General somatic efferent (motor) Cranial Nerve IV: Trochlear n