The chief sensory nerve of the face and the motor nerve of the muscles of chewing. The nuclei of the nerve are in the mesencephalon and in the pons and extend down into the cervical portion of the spinal cord. The nerve emerges by two sensory and motor roots from the pons and enters a cavity of the dura mater at the temporal bone, where its sensory root expands to form the trigeminal ganglion that forms three branches that are designated ophthalmic, maxillary, and mandibular. Also called fifth cranial nerve, trigeminus.