Trigeminal nerve

A crucial nerve responsible for sensation in the face and motor functions such as chewing.

The trigeminal nerve, known as cranial nerve V, is the largest of the cranial nerves and has both sensory and motor functions. It is primarily responsible for transmitting sensory information from the face to the brain, including touch, pain, and temperature sensations. It also controls the muscles involved in mastication, or chewing.

Terminologia Anatomica

nervus-trigeminalis

System

Nervous system

Function

The trigeminal nerve serves several important roles in the body. It is divided into three branches: the ophthalmic, maxillary, and mandibular nerves. The ophthalmic branch is responsible for sensory innervation of the forehead, upper eyelids, and the front part of the scalp, allowing the detection of touch and pain in these areas. The maxillary branch provides sensory input from the middle part of the face, including the cheeks, upper lip, and nasal cavity. The mandibular branch, which also contains motor fibers, innervates the lower jaw, enabling the movement of the chewing muscles. This dual function makes the trigeminal nerve vital for both sensation and the mechanical function of eating, providing essential feedback to the brain about the environment and coordinating muscular activity.

Location

The trigeminal nerve originates from the brainstem, specifically the pons, where it emerges from the anterior aspect. After exiting the brain, it divides into its three branches. The ophthalmic nerve travels through the superior orbital fissure to the orbit, where it branches into several smaller nerves that extend to the forehead and scalp. The maxillary nerve exits the skull through the foramen rotundum and traverses to the maxillary area, while the mandibular nerve passes through the foramen ovale and descends towards the lower jaw. Because of its extensive branching, the trigeminal nerve innervates a wide area of the face.

Did You Know?

The trigeminal nerve is responsible for sensations such as touch, temperature, and pain, making it vital for everyday experiences.
It is involved in the reflex actions such as the 'blink reflex' when the cornea is touched, which helps protect the eye.
Trigeminal neuralgia, a condition affecting the trigeminal nerve, is known for causing severe facial pain and is sometimes called 'the suicide disease' due to the intensity of the discomfort.
This nerve is the only cranial nerve that has both sensory and motor functions, against the typical function of cranial nerves that usually focus on either one.