The trigeminal nerve (the fifth cranial nerve, or simply CN V) is a nerve responsible for sensation in the face and motor functions such as biting and chewing. The largest of the cranial nerves, its name ("trigeminal" = tri-, or three and -geminus, or twin; thrice-twinned) derives from the fact that each trigeminal nerve (one on each side of the pons) has three major branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3).