Trigeminal nerve

The trigeminal nerve contains both sensory and motor fibers. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing.

As you can see from the diagram, the nerve’s main root passes by the ear and contains the sensory information from all parts of the face.

Trigeminal nerve

The trigeminal nerve is the largest of the cranial nerves. Its name derives from the fact that each nerve, one on each side of the pons, has three major branches:

• the ophthalmic nerve - The ophthalmic nerve (V₁) carries sensory information from the scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges (the dura and blood vessels).

• the maxillary nerve  - The maxillary nerve (V₂) carries sensory information from the 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.

• the mandibular nerve - The mandibular nerve (V₃) carries sensory information from the lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw), parts of the external ear, and parts of the meninges. The mandibular nerve carries touch/position and pain/temperature sensation from the mouth. It does not carry taste sensation.

The three branches converge on the trigeminal ganglion.

From the trigeminal ganglion, a single large sensory root enters the brainstem at the level of the pons. Immediately adjacent to the sensory root, a smaller motor root emerges from the pons at the same level.  So here we have the link with the brain stem – there is a direct link with this nerve and the brain stem that can induce various functions in the reticular formation – the seat of spiritual experience.