Trigeminal Nerve

(redirected from Trigeminal system)
Also found in: Dictionary, Thesaurus, Medical.

trigeminal nerve

[trī′jem·ə·nəl ′nərv]
(neuroscience)
The fifth cranial nerve in vertebrates; either of a pair of composite nerves rising from the side of the medulla, and with three great branches: the ophthalmic, maxillary, and mandibular nerves.

Trigeminal Nerve

 

the fifth pair of cranial nerves. It contains sensory, motor, and autonomic fibers.

The nuclei of the trigeminal nerve are located in the brain stem. The fibers of the trigeminal nerve that constitute the larger, or posterior, root pass from the brain stem to the apex of the temporal bone, where the trigeminal ganglion is located. Three branches depart from the trigeminal ganglion, as follows. The ophthalmic (sensory) nerve leaves the skull through the superior orbital fissure and innervates the upper eyelids, the conjunctiva, the skin of the forehead, and the anterior part of the scalp. The superior maxillary (sensory) nerve leaves the skull through the foramen rotundum, enters the pterygopalatine fossa, and innervates the skin of the lower lid, the cheek and nose, the mucosa of the nasal cavity, and the upper jaw. The inferior maxillary nerve (which is joined to the smaller, or anterior, root of the trigeminal nerve, containing the motor fibers) leaves the skull through the foramen ovale and innervates the skin of the lower part of the face, the mucosa of the cheeks and tongue, the lower jaw, and the muscles of mastication.

The trigeminal nerve takes part in many reflexes, including the corneal and mandibular (jaw) reflex. The most common disease of the trigeminal nerve is neuralgia, manifested by attacks of acute pain in the zone of innervation. Other diseases of the trigeminal nerve, including neuritis and infection with the virus of herpes zoster, are accompanied by sensory and motor disturbances in the zone of innervation.

V. A. KARLOV

References in periodicals archive ?
[Na.sub.v]1.7 and Nav1.8 are expressed together in the trigeminal system, and, by simultaneous activation, they generate APs that are critical for pain sensation [17,23].
The mechanism by which dexmedetomidine-stimulated [alpha]2-adrenoceptors inhibit [I.sub.Na] in the trigeminal system has not been well described yet.
With consideration, the broad and sensitizing effects of cervical pain having further effects on the trigeminal system via convergence is a reasonable theoretical assumption.
Given the sensitivity of the trigeminal system through the capsaicin-sensitive vanilloid receptor (Nakagawa and Hiura, 2006; Silver et al., 2006) and the similarity in chemical structure of the quinones and vanillin moiety, it would seem prudent to test the arthropod-produced quinones on the trigeminal system and specifically on the family of vanilloid receptors.
Fischer, "CGRP and NO in the trigeminal system: mechanisms and role in headache generation," Headache: The Journal of Head and Face Pain, vol.
From this basis, it can be argued that in chronic TMD an alteration in the trigeminal system afferents is present.