Cranial Nerve V (Trigeminal Nerve)

This is a large mixed nerve that has three branches: the ophthalmic branch, maxillary branch and mandibular branch. Although it is a mixed nerve its sensory functions are much more extensive than its motor functions. The motor fibers of the trigeminal nerve are found in the mandibular branch that innervates mouth muscles used in mastication and also other muscles on the floor of the mouth. The sensory fibers of the mandibular branch respond to sensation from the teeth and gums of the lower jaw, parts of the tongue, auricle of the ear and lower part of the face. The ophthalmic sensory branch has sensory fibers that respond to touch, temperature and pain from the anterior half of the scalp, skin of the forehead, upper eyelid, surface of the eyeball, and side of the nose. The maxillary branch responds to sensation from the lower eyelid, palate and portion of the pharynx, teeth and gums of the upper jaw