Biomaterial Database

Unmyelinated fibers in the trigeminal motor root. Possible relationship to the results of trigeminal rhizotomy. 1978

R F Young

Spinal ventral roots have been shown by electron microscopy to contain a substantial number of unmyelinated fibers. Physiological studies have confirmed that many of these subserve a sensory function. In this investigation the fiber spectrum of the human trigeminal motor root was studied by electron microscopy and it was determined that up to 20% of fibers were unmyelinated. This accounted for approximately 300 to 1000 fibers per root. Since visceral efferent fibers are thought not to occur in the trigeminal root, it appears likely that these unmyelinated fibers may be afferent in nature. It is believed that the presence of a substantial number of unmyelinated fibers in the trigeminal motor root may account for residual sensation or failure of pain relief after rhizotomy of the trigeminal portio major root.

UI	MeSH Term	Description	Entries
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D010146	Pain	An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.	Suffering, Physical,Ache,Pain, Burning,Pain, Crushing,Pain, Migratory,Pain, Radiating,Pain, Splitting,Aches,Burning Pain,Burning Pains,Crushing Pain,Crushing Pains,Migratory Pain,Migratory Pains,Pains, Burning,Pains, Crushing,Pains, Migratory,Pains, Radiating,Pains, Splitting,Physical Suffering,Physical Sufferings,Radiating Pain,Radiating Pains,Splitting Pain,Splitting Pains,Sufferings, Physical
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012677	Sensation	The process in which specialized SENSORY RECEPTOR CELLS transduce peripheral stimuli (physical or chemical) into NERVE IMPULSES which are then transmitted to the various sensory centers in the CENTRAL NERVOUS SYSTEM.	Sensory Function,Organoleptic,Function, Sensory,Functions, Sensory,Sensations,Sensory Functions
D013126	Spinal Nerve Roots	Paired bundles of NERVE FIBERS entering and leaving the SPINAL CORD at each segment. The dorsal and ventral nerve roots join to form the mixed segmental spinal nerves. The dorsal roots are generally afferent, formed by the central projections of the spinal (dorsal root) ganglia sensory cells, and the ventral roots are efferent, comprising the axons of spinal motor and PREGANGLIONIC AUTONOMIC FIBERS.	Dorsal Roots,Spinal Roots,Ventral Roots,Dorsal Root,Nerve Root, Spinal,Nerve Roots, Spinal,Root, Dorsal,Root, Spinal,Root, Spinal Nerve,Root, Ventral,Roots, Dorsal,Roots, Spinal,Roots, Spinal Nerve,Roots, Ventral,Spinal Nerve Root,Spinal Root,Ventral Root
D014276	Trigeminal Nerve	The 5th and largest cranial nerve. The trigeminal nerve is a mixed motor and sensory nerve. The larger sensory part forms the ophthalmic, mandibular, and maxillary nerves which carry afferents sensitive to external or internal stimuli from the skin, muscles, and joints of the face and mouth and from the teeth. Most of these fibers originate from cells of the TRIGEMINAL GANGLION and project to the TRIGEMINAL NUCLEUS of the brain stem. The smaller motor part arises from the brain stem trigeminal motor nucleus and innervates the muscles of mastication.	Cranial Nerve V,Fifth Cranial Nerve,Nerve V,Nervus Trigeminus,Cranial Nerve, Fifth,Fifth Cranial Nerves,Nerve V, Cranial,Nerve Vs,Nerve, Fifth Cranial,Nerve, Trigeminal,Trigeminal Nerves,Trigeminus, Nervus