The trigeminal nerve has a sensory component to the face, cornea, nasal mucosa, teeth, tympanic membrane and anterior 2/3 of the tongue (see notes).
The trigeminal nerve has three major branches:
- the ophthalmic nerve , the maxillary nerve and the mandibular nerve
The ophthalmic and maxillary nerves are purely sensory. The mandibular nerve has both sensory and motor functions.
- ophthalmic nerve
- sensory distribution - front of scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose), the nasal mucosa, the frontal sinuses and parts of the meninges
- maxillary nerve
- sensory distribution - lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges
- mandibular nerve
- sensory distribution - lower lip, the lower teeth and gums, the floor of the mouth, the anterior 2/3 of the tongue, the chin and jaw (except the angle of the jaw, which is supplied by C2-C3), parts of the external ear, and parts of the meninges
- mandibular nerve carries touch/position and pain/temperature sensation from the mouth
The trigeminal nerve is the principal motor nerve supplying the muscles of mastication.
- the mandibular nerve does not carry taste taste sensation - however one of its branches, the lingual nerve carries multiple types of nerve fibres that do not originate in the mandibular nerve
- taste fibres from the anterior 2/3 of the tongue are initially carried in the lingual nerve (which is anatomically a branch of the mandibular neve) - these fibres then enter the chorda tympani, a branch of cranial nerve VII