abducens nerve [L, abducere, to take away] , either of the paired sixth cranial nerves. It arises in the pons near the fourth ventricle, leaves the brainstem between the medulla oblongata and pons, and passes through the cavernous sinus and the superior orbital fissure. It controls the lateral rectus muscle, turning the eye outward. Also called abducent, nervus abducens, sixth cranial nerve.