| mesencephalic tract of trigeminal nerve | <anatomy, nerve> Located alongside the central substance of the midbrain and composed of primary sensory fibres, the cells of origin of which compose the mesencephalic nucleus of the trigeminus. Synonym: tractus mesencephalicus nervi trigemini. (05 Mar 2000) |
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| roots of trigeminal nerve | <anatomy, nerve> Collective term for the sensory root of trigeminal nerve and motor root of trigeminal nerve. Synonym: radices nervi trigemini. (05 Mar 2000) |
| motor nucleus of trigeminal nerve | <anatomy, nerve> A group of motor neurons innervating the muscles of mastication (masseter, temporalis, internal and external pterygoid muscles) and the musculi tensor tympani and tensor veli palatini. The nucleus lies in the upper pontine tegmentum medial to the main sensory nucleus of the trigeminus. Synonym: nucleus motorius nervi trigemini, masticatory nucleus, motor nucleus of trigeminus, nucleus masticatorius. (05 Mar 2000) |
| motor root of trigeminal nerve | <anatomy, nerve> The smaller root of the trigeminal nerve, composed of fibres originating from the trigeminal motor nucleus and emerging from the pons medial to the much larger sensory root, to join the mandibular nerve; it carries motor and proprioceptive fibres to the muscles derived from the first bronchial (mandibular) arch, including the four muscles of mastication, plus the mylohyoid, anterior belly of the digastric, and the tensores tympani and veli palati. Synonym: radix motoria nervi trigemini, masticator nerve, portio minor nervi trigemini. (05 Mar 2000) |
| principal sensory nucleus of trigeminal nerve | <anatomy, nerve> The term commonly used to designate the nucleus pontis nervi trigeminalis; located in pons lateral to the motor trigeminal nucleus; receives primary sensory (touch and pressure) input via the trigeminal nerve, projects to ventral posteromedial nucleus of thalamus. Synonym: nucleus sensorius principalis nervi trigemini, nucleus sensorius superior nervi trigemini, principal sensory nucleus of the trigeminus. (05 Mar 2000) |
| sensory root of trigeminal nerve | <anatomy, nerve> The large sensory root of the trigeminal (or fifth cranial) nerve, extending from the semilunar ganglion into the pons through the middle cerebellar peduncle or brachium pontis, immediately lateral to the small motor root. Synonym: radix sensoria nervi trigemini, portio major nervi trigemini. (05 Mar 2000) |
| spinal tract of trigeminal nerve | <anatomy, nerve> A compact fibre bundle, comma-shaped on transverse section, composed of primary sensory fibres of the portio major of the trigeminal nerve, descending from the level of the entrance of the trigeminus in the upper pons down through the dorsolateral region of the rhombencephalic tegmentum along the lateral side of the descending or spinal nucleus of the trigeminus, emerging on the dorsolateral surface of the lower medulla oblongata as the tuberculum cinereum, and continuing as far as the second cervical segment of the spinal cord. Its fibres are distributed to the descending or spinal nucleus of the trigeminus. Synonym: tractus spinalis nervi trigemini, descending tract of trigeminal nerve, tractus descendens nervi trigemini. (05 Mar 2000) |
| spinal trigeminal nucleus | The long sensory nucleus extending from the caudal border of the pontine sensory nucleus of the trigeminus down through the lateral region of the rhombencephalon into the upper three segments of the spinal cord's dorsal horn; it receives the fibres of the sensory root of the trigeminal nerve which descend along its lateral border as the spinal tract of trigeminal nerve. Synonym: nucleus tractus spinalis nervi trigemini, descending nucleus of the trigeminus, spinal nucleus of the trigeminus. (05 Mar 2000) |
| descending tract of trigeminal nerve | <anatomy, nerve> A compact fibre bundle, comma-shaped on transverse section, composed of primary sensory fibres of the portio major of the trigeminal nerve, descending from the level of the entrance of the trigeminus in the upper pons down through the dorsolateral region of the rhombencephalic tegmentum along the lateral side of the descending or spinal nucleus of the trigeminus, emerging on the dorsolateral surface of the lower medulla oblongata as the tuberculum cinereum, and continuing as far as the second cervical segment of the spinal cord. Its fibres are distributed to the descending or spinal nucleus of the trigeminus. Synonym: tractus spinalis nervi trigemini, descending tract of trigeminal nerve, tractus descendens nervi trigemini. (05 Mar 2000) |
| trigeminal | <anatomy> Of, pertaining to, or designating, the fifth pair of cranial nerves, which divide on each side of the head into three main branches distributed to the orbits, jaws, and parts of the mouth; trifacial. See: Trigeminous. Source: Websters Dictionary (01 Mar 1998) |
| trigeminal caudal nucleus | The caudal portion of the nucleus of the spinal trigeminal tract (trigeminal nucleus, spinal), a nucleus involved with pain and temperature sensation. (12 Dec 1998) |
| trigeminal cave | The cleft in the meningeal layer of dura of the middle cranial fossa near the tip of the petrous part of the temporal bone; it encloses the roots of the trigeminal nerve and the trigeminal ganglion. Synonym: cavum trigeminale, Meckel's cavity, Meckel's space, trigeminal cavity. (05 Mar 2000) |
| trigeminal cavity | The cleft in the meningeal layer of dura of the middle cranial fossa near the tip of the petrous part of the temporal bone; it encloses the roots of the trigeminal nerve and the trigeminal ganglion. Synonym: cavum trigeminale, Meckel's cavity, Meckel's space, trigeminal cavity. (05 Mar 2000) |
| trigeminal crest | That part of the cranial neural crest from which the ganglion of the fifth cranial nerve develops. (05 Mar 2000) |
| trigeminal decompression | Decompression of the trigeminal nerve root. (05 Mar 2000) |