The trigeminal nerve, cranial nerve V, provides sensory innervation to the face and structures in the oral and nasal cavities; in addition, its motor component innervates the muscles of mastication and other skeletal muscles. Fine (discriminatory) tactile, general (light) tactile, proprioceptive, thermal, and pain sensory modalities are conveyed to the trigeminal nuclei in the brain stem. Axons from the sensory trigeminal nuclei contribute to important reflex circuits and relay sensory modalities to the thalamus for further integration. Thalamocortical projections relay sensations to the face area of the contralateral cerebral hemisphere, specifically the postcentral gyrus.
The trigeminal system is frequently involved in important clinical conditions because its peripheral and central components have extensive anatomic distributions in the face, cranial cavity and brain stem.
Peripherial Distribution of the Trigeminal Nerve
The Three Divisions of the Trigeminal Nerve
KeywordsTrigeminal Nerve Trigeminal Neuralgia Trigeminal Ganglion Trigeminal Nucleus Sensory Innervation
The invaluable assistance of Ms. Mary Gail Engle and Dr. Bruce Maley, University of Kentucky, in the preparation of illustrations for this chapter is greatly appreciated. Professor Marina Del Fiacco, University of Cagliari, Monserrato, Italy, provided the illustrations of immunohistochemical preparations for SP and CGRP in the human trigeminal system (Fig. 4). Her generosity is greatly appreciated. The Weigert-stained sections of human brain stem were photographed from the Yakovlev Collection housed at the Armed Forces Institute of Pathology, Washington, DC.
- Brodal A. Cranial nerves - the trigeminal nerve. In: Neurological Anatomy in Relation to Clinical Medicine, 3rd ed. New York: Oxford University Press, 1981:508–532.Google Scholar
- Crino PB, Galetta S. Cranial nerve V. In: Goetz CG, ed. Textbook of Clinical Neurology, 2nd ed. Philadelphia: Saunders, 2003:165–179.Google Scholar
- Hassanali J Quantative and somatotopic mappings of neurones in trigeminal mesencephalic nucleus and ganglion innervating teeth in monkey and baboon. Arch Oral Biol 1997;42:673–682.Google Scholar
- Johnson LR, Westrum LE, Henry MA. Anatomic organization of the trigeminal system and the effects of deafferentation. In: Fromm GH, Sessle BJ. ed. Trigeminal Neuralgia: Current Concepts Regarding Pathogenesis and Treatment. Boston: Butterworth Heinemann, 1991:27–69.Google Scholar
- Kiernan JA. Cranial nerves. In: Barr’s The Human Nervous System, 8th ed. Baltimore: 2005; 121–155.Google Scholar
- Paxinos G, Törk I, Halliday G, Mehler WR. Human homologs to brain stem nuclei identified in other animals as revealed by acetylcholinesterase activity. In: Paxinos G, ed. The Human Nervous System. New York: Academic Press, 1990:149–202.Google Scholar
- Siegel A, Sapru HN. The cranial nerves. In: Essential Neuroscience, Baltimore: Lippincott Williams & Wilkins, 2006:223–252.Google Scholar
- Young RF. The trigeminal nerve and its central pathways. In: Rovit RL, Murali R, Jannetta PJ, eds. Trigeminal Neuralgia. Baltimore: Williams and Wilkins, 1990:27–52.Google Scholar