The Trigeminal System

Abstract

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.