any of the twelve couples of nerves that stem directly from the brain and are dispersed primarily to constructions in the neck and head. They are: (I) olfactory nerve, (II) optic nerve, (III) oculomotor nerve, (IV) trochlear nerve, (V) trigeminal nerve, (VI abducens nerve, (VII) facial nerve, (VIII) vestibular nerve, (IX) glossopharyngeal nerve, (X) vagus nerve, (XI) accessory nerve, and (XII) hypoglossal nerve.
CRANIAL NERVE: “Neurosurgeons must be very careful not to disturb cranial nerves during surgery.”