Which is the largest cranial nerve?

There are 12 cranial nerves in the body, all originating in the brain. They come in pairs and connect different body areas and organs to the brain. The trigeminal nerve is the largest of your cranial nerves and has both sensory and motor functions. The trigeminal nerve originates from a group of nuclei — which is a collection of nerve cells — in the midbrain and medulla regions of your brainstem. Eventually, these nuclei form a separate sensory root and motor root.

The trigeminal nerve has three divisions, which are:

-- Ophthalmic. The ophthalmic division sends sensory information from the upper part of your face, including your forehead, scalp, and upper eyelids.

-- Maxillary. This division communicates sensory information from the middle part of your face, including your cheeks, upper lip, and nasal cavity.

-- Mandibular. The mandibular division has both a sensory and a motor function. It sends sensory information from your ears, lower lip, and chin. It also controls the movement of muscles within your jaw and ear.

The sensory root of your trigeminal nerve branches into the ophthalmic, maxillary, and mandibular divisions. The motor root of your trigeminal nerve passes below the sensory root and is only distributed into the mandibular division.