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A whitish cordlike structure composed of one or more bundles (fascicles) of myelinated or unmyelinated n. fibers, or more often mixtures of both, coursing outside the central nervous system, together with connective tissue within the fascicle and around the neurolemma of individual n. fibers (endoneurium), around each fascicle (perineurium), and around the entire n. and its nourishing blood vessel s (epineurium), by which stimuli are transmitted from the central nervous system to a part of the body or the reverse. N. branches are given in the definition of the major n.; many are also listed and defined under branch. SYN: nervus [TA]. [L. nervus]
- abdominopelvic splanchnic nerves visceral branches of the sympathetic trunks conveying presynaptic sympathetic fibers to and visceral afferent fibers from the prevertebral ganglia and para-aortic/hypogastric plexuses for the innervation of viscera located below the diaphragm. The greater, lesser, lowest, lumbar, and sacral splanchnic nerves belong to this group.
- abducent n. [CN VI] [TA] a small motor n. supplying the lateral rectus muscle of the eye; its origin is in the dorsal part of the tegmentum of the pons just below the surface of the rhomboid fossa, and it emerges from the brain in the fissure between the medulla oblongata and the posterior border of the pons (medullopontine sulcus); it enters the dura of the clivus and passes through the cavernous sinus, entering the orbit through the superior orbital fissure. SYN: nervus abducens [CN VI] [TA], abducens n., abducent (2), sixth cranial n. [CN VI].
- accelerator nerves certain of the cardiopulmonary splanchnic nerves establishing the sympathetic innervation of the heart; originating from ganglion cells of the superior, middle, and inferior cervical ganglion of the sympathetic trunk, the unmyelinated efferent fibers of the accelerator nerves stimulate an increase in the heart rate.
- accessory n. [CN XI] [TA] arises by two sets of roots: the presumed cranial, emerging from the side of the medulla, and spinal, emerging from the ventrolateral part of the first five cervical segments of the spinal cord; these roots unite to form the accessory n. trunk, which divides into two branches, internal and external; the internal branch, carrying fibers of the cranial root, unites with the vagus in the jugular foramen and supplies the muscles of the pharynx, larynx, and soft palate; the external branch continues independently through the jugular foramen to supply the sternocleidomastoid and trapezius muscles. While the accessory n. was originally believed to have cranial and spinal roots, it is now the general view that the so-called cranial root is actually a portion of the vagus n.. SYN: nervus accessorius [CN XI] [TA], accessorius willisii, eleventh cranial n. [CN XI], spinal accessory n..
- accessory phrenic nerves [TA] accessory n. strands that arise from the fifth cervical n., often as branches of the n. to the subclavius, passing downward to join the phrenic n.. SYN: nervi phrenici accessorii [TA].
- afferent n. a n. conveying impulses from the periphery to the central nervous system. SYN: centripetal n., esodic n..
- anococcygeal n. small n. arising from the coccygeal plexus, supplying the skin over the coccyx. SYN: nervus anococcygeus.
- anterior ampullary n. [TA] a branch of the utriculoampullar n. that supplies the crista ampullaris of the anterior semicircular duct. SYN: nervus ampullaris anterior [TA].
- anterior auricular nerves [TA] branches of the auriculotemporal n. that supply the tragus and upper part of the auricle. SYN: nervi auriculares anteriores [TA].
- anterior ethmoidal n. [TA] a branch of the nasociliary n.; passes through anterior ethmoidal foramen on superomedial wall of orbit into cranial cavity, giving rise to anterior meningeal nerves, then passes through cribriform plates into nasal cavity, supplying anterosuperior nasal mucosa. SYN: nervus ethmoidalis anterior [TA].
- anterior interosseous n. [TA] a branch of the median arising in the elbow region, running on interosseous membrane, supplying the flexor pollicis longus, part of flexor digitorum profundus and the pronator quadratus muscles, as well as radiocarpal and intercarpal joints. SYN: nervus interosseus antebrachii anterior [TA], anterior antebrachial n., nervus antebrachii anterior, volar interosseous n..
- anterior labial nerves [TA] branches of the ilioinguinal n. distributed to the labia majora, mons pubis, and adjacent thigh. SYN: nervi labiales anteriores [TA].
- anterior scrotal nerves [TA] the branches of the ilioinguinal n., distributed to the skin of the root of the penis, mons pubis, adjacent thigh, and anterior surface of the scrotum. SYN: nervi scrotales anteriores [TA].
- anterior superior alveolar nerves [TA] the branches of the superior alveolar n. that supply the incisors, canines, premolars, and first molar by their contributions to the superior dental plexus. SYN: anterior superior alveolar branches of infraorbital n., rami alveolares superiores anteriores nervi infraorbitalis.
- aortic n. a branch of the vagus that ends in the aortic arch and base of the heart; composed entirely of afferent fibers; its stimulation elicits a brainstem reflex that causes slowing of the heart, dilation of the peripheral vessels, and a fall in blood pressure. SYN: Cyon n., depressor n. of Ludwig, Ludwig n..
- augmentor nerves SYN: cervical splanchnic nerves.
- auriculotemporal n. [TA] a branch of the mandibular, usually arising by two roots embracing the middle meningeal artery; it passes through the parotid gland conveying postsynaptic parasympathetic secretomotor fibers from the otic ganglion, and continuing to terminate in the skin of the temple and scalp; also sends branches to the external acoustic meatus, tympanic membrane, and auricle as well as a communicating branch to the facial n.. SYN: nervus auriculotemporalis [TA].
- autonomic n. a bundle of autonomic n. fibers outside of the central nervous system belonging or relating to the autonomic (visceral motor) nervous system. SYN: nervus autonomicus [TA].
- axillary n. [TA] arises from the posterior cord of the brachial plexus in the axilla, passes laterally and posteriorly through quadrangular space with the posterior circumflex humeral artery, winding round the surgical neck of the humerus to supply the deltoid and teres minor muscles, terminating as the superior lateral brachial cutaneous n.. SYN: nervus axillaris [TA], circumflex n..
- baroreceptor n. SYN: pressoreceptor n..
- Bock n. SYN: pharyngeal n..
- buccal n. [TA] a sensory branch of the mandibular division of the trigeminal n.; it passes downward, emerging from beneath the ramus of the mandible to run forward on the buccinator muscle, piercing (but not supplying) it to supply the buccal mucous membrane and skin of the cheek near the angle of the mouth. SYN: nervus buccalis [TA], buccinator n., long buccal n..
- buccinator n. SYN: buccal n..
- cardiopulmonary splanchnic nerves visceral branches of the sympathetic trunks conveying postsynaptic sympathetic fibers to and visceral afferent fibers from viscera located above the diaphragm, mainly via the cardiac, pulmonary, and esophageal plexuses. The cervical and upper thoracic splanchnic nerves are part of this group.
- caroticotympanic nerves two sympathetic branches from the internal carotid plexus to the tympanic plexus. SYN: nervi caroticotympanicus, small deep petrosal n..
- cavernous nerves of clitoris [TA] nerves corresponding to the cavernous nerves of penis in the male, arising from the vesicular portion of the pelvic plexus. SYN: nervi cavernosi clitoridis [TA], cavernous plexus of clitoris.
- cavernous nerves of penis [TA] two nerves, major and minor, derived from the prostatic portion of the pelvic plexus supplying sympathetic and parasympathetic fibers to the helicine arteries and arteriorvenous anastomoses of the corpus cavernosum stimulating erection. SYN: nervi cavernosi penis [TA], cavernous plexus of penis.
- centrifugal n. SYN: efferent n..
- centripetal n. SYN: afferent n..
- cervical nerves [C1–C8] spinal nerves arising from the cervical segments of the spinal cord. SYN: nervi cervicales [C1–C8].
- cervical splanchnic nerves visceral branches arising from the superior, middle, and inferior (stellate) cervical ganglia; they include the superior, middle, and inferior cervical cardiac nerves and are part of the cardiopulmonary splanchnic nerves. SYN: augmentor nerves.
- circumflex n. SYN: axillary n..
- coccygeal n. [Co] [TA] a small n., the lowest of the spinal nerves, entering into the formation of the coccygeal plexus. SYN: nervus coccygeus [Co] [TA].
- cochlear n. [TA] the part of the vestibulocochlear n. [CN VIII] peripheral to the cochlear root; composed of the central n. processes of the bipolar neurons of the spiral ganglion, which have their peripheral processes on the four rows of neuroepithelial cells (hair cells) of the spiral organ. SEE ALSO: cochlear root of VIII n.. SYN: nervus cochlearis [TA], auditory n., cochlear part of vestibulocochlear n., inferior part of vestibulocochlear n., pars cochlearis nervi vestibulocochlearis.
- common fibular n. [TA] one of the terminal divisions of the sciatic n., diverging from the tibial n. at the upper end of the popliteal fossa, then coursing with the biceps tendon along the lateral portion of the popliteal space to wind around the neck of the fibula where it divides into the superficial and deep peroneal nerves. The common peroneal n., or its deep branch, is the most commonly injured n., being located in a lateral subcutaneous position at the fibular neck; a lesion causes a loss of ability to dorsiflex the foot ("foot drop"). SYN: nervus fibularis communis [TA], common peroneal n., nervus peroneus communis.
- common palmar digital nerves [TA] four nerves in the palm that send branches (proper palmar digital nerves) to adjacent sides of two digits; three are branches of the median n., one is from the ulnar n.. SYN: nervi digitales palmares communes [TA].
- common plantar digital nerves [TA] three nerves derived from the medial plantar n. and one from the lateral plantar n. that supply the skin overlying the metatarsals and terminate as proper plantar digital nerves to the side of each toe. SYN: nervi digitales plantares communes [TA].
- cranial nerves [TA] those nerves that emerge from, or enter, the cranium or skull, in contrast to the spinal nerves, which emerge from the spine or vertebral column. The twelve paired cranial nerves are the olfactory [CN I], optic [CN II], oculomotor [CN III], trochlear [CN IV], trigeminal [CN V], abducent [CN VI], facial [CN VII], vestibulocochlear [CN VIII], glossopharyngeal [CN IX], vagal [CN X], accessory [CN XI], and hypoglossal [CN XII] nerves. SYN: nervi craniales [TA].
- crural interosseous n. [TA] a n. given off from one of the muscular branches of the tibial n. which passes down over the posterior surface of the interosseous membrane supplying it and the two bones of the leg. SYN: nervus interosseus cruris [TA], interosseous n. of leg.
- cutaneous n. [TA] a mixed n. supplying a region of the skin, including its sensory endings, blood vessel s, smooth muscle and glands. SYN: nervus cutaneus [TA].
- deep fibular n. [TA] one of the terminal branches of the common peroneal n., arising at the fibular neck and passing into the anterior compartment of the leg; it supplies the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius muscles in the leg, then crosses the ankle joint to supply the muscles on the dorsum of the foot (extensors hallucis and digitorum brevis), becoming cutaneous to innervate adjacent sides of the great and second toes. SYN: nervus fibularis profundus [TA], deep peroneal n., nervus peroneus profundus, anterior tibial n..
- deep petrosal n. [TA] the deep petrosal branch of the internal carotid plexus, which joins the greater petrosal n. at the entrance of the pterygoid canal forming the n. of the pterygoid canal and thus provides postsynaptic fibers to the pterygopalatine ganglion. SYN: nervus petrosus profundus [TA], radix sympathica ganglii pterygopalatini, sympathetic root of pterygopalatine ganglion.
- deep temporal nerves [TA] two branches, anterior and posterior, from the mandibular n., supplying the temporalis muscle and periosteum of the temporal fossa. SYN: nervi temporales profundi [TA].
- dental n. 1. layperson's term for a dental pulp; 2. branches of the inferior and superior alveolar nerves to the teeth. See inferior alveolar n., superior alveolar nerves.
- dorsal n. of clitoris [TA] the deep terminal branch of the pudendal, supplying especially the glans clitoridis after passing through the deep perineal musculature, to run along the dorsum of the clitoral shaft. SYN: nervus dorsalis clitoridis [TA].
- dorsal digital nerves of deep fibular n. [TA] terminal sensory portion of the deep fibular (peroneal) n. on the dorsum of the foot, remaining after the motor branches to the extensor digitorum brevis and extensor hallucis brevis muscles have been supplied; provides cutaneous innervation to a small, wedge-shaped area that includes the adjacent sides of the great and second toes. SYN: nervi digitales dorsales nervi fibularis profundi [TA].
- dorsal digital nerves of foot [TA] nerves supplying the skin of the dorsal aspect of the proximal and middle phalanges of the toes. See dorsal digital nerves of superficial fibular n., dorsal digital nerves of deep fibular n.. SYN: nervi digitales dorsales pedis [TA], dorsal nerves of toes.
- dorsal digital nerves of hand [TA] terminal branches of the radial and ulnar nerves in the hand supplying the skin of the dorsal surface of the proximal and middle phalanges of the fingers. See dorsal digital nerves of ulnar n.. SYN: dorsal digital nerves, nervi digitales dorsales.
- dorsal digital nerves of superficial fibular n. [TA] nerves arising in the lateal fibular/peroneal) compartment of the leg that pass to the dorsum of the foot, supplying the skin of most of the dorsum of the foot and dorsal aspect of the toes, with the exception of a small wedge-shaped area including the adjacent sides of the great and second toes. SYN: nervi digitales dorsales nervi fibularis superficialis [TA].
- dorsal digital nerves of ulnar n. [TA] nerves arising from the dorsal branch of the ulnar n. supplying the skin of the dorsal aspect of the little and ulnar half of the ring fingers and adjacent area of the dorsum of the hand. SYN: nervi digitales dorsales nervi ulnaris [TA].
- dorsal n. of penis [TA] the deep terminal branch of the pudendal nerves that runs through the deep perineal muscles giving branches, then runs along the dorsum of the penis, supplying the skin of the penis, the prepuce, the corpora cavernosa, and the glans. SYN: nervus dorsalis penis [TA].
- dorsal scapular n. [TA] arises from ventral primary rami of the fifth to seventh cervical nerves and passes downward to supply the levator scapulae and the rhomboideus major and minor muscles. SYN: nervus dorsalis scapulae [TA], dorsal n. of scapula, n. to rhomboid, posterior scapular n..
- efferent n. a n. conveying impulses from the central nervous system to the periphery. SYN: centrifugal n., exodic n..
- eighth n. SYN: vestibulocochlear n. [CN VIII].
- eighth cranial n. [CN VIII] SYN: vestibulocochlear n. [CN VIII].
- exodic n. SYN: efferent n..
- n. to external acoustic meatus [TA] a branch of the auriculotemporal n. supplying the lining of the external acoustic meatus. SYN: nervus meatus acustici externi [TA].
- external carotid nerves [TA] cephalic arterial ramus of the sympathetic trunk, conveying a number of sympathetic n. fibers extending from the superior cervical ganglion to the external carotid artery to form the external carotid plexus. SYN: nervi carotici externi [TA].
- facial n. [CN VII] [TA] n. with origin in the tegmentum of the lower portion of the pons; it emerges from the brain at the posterior border of the pons; it leaves the cranial cavity through the internal acoustic meatus where it is joined by the intermediate n., traverses the facial canal in the petrous portion of the temporal bone, and makes its exit through the stylomastoid foramen; after supplying the stapedius, occipitalis, auricular, stylohyoid, and posterior belly of the digastric muscles; its main trunk ramifies within the parotid gland forming the intraparotid plexus, the various branches of which pass to the muscles of facial expression. SYN: nervus facialis [CN VII] [TA], motor n. of face, seventh cranial n. [CN VII].
- femoral n. [TA] arises as a branch of the lumbar plexus, conveying fibers from the second, third, and fourth lumbar nerves through the substance of the psoas muscle and enters the thigh via the retroinguinal muscular space posterior to the inguinal ligament, lateral to the femoral vessels; it arborizes within the femoral triangle into muscle branches to the sartorius, pectineus, and quadriceps muscles and anterior femoral cutaneous branches to the skin of the anterior and medial region of the thigh; its terminal branch is the saphenous n. by which it supplies the skin of the medial leg and foot. SYN: nervus femoralis [TA], anterior crural n..
- fifth cranial n. [CN V] SYN: trigeminal n. [CN V].
- fourth lumbar n. [L4] [TA] the ventral branch of the n. is forked to enter into the formation of both lumbar and sacral plexuses. SYN: furcal n., nervus furcalis.
- frontal n. [TA] a branch of the ophthalmic n. that divides within the orbit into the supratrochlear and the supraorbital nerves. SYN: nervus frontalis [TA].
- gangliated n. a sympathetic n..
- genitocrural n. SYN: genitofemoral n..
- genitofemoral n. [TA] arises from the first and second lumbar nerves, passes distally along the anterior surface of psoas major muscle and divides into genital and femoral branches. SYN: nervus genitofemoralis [TA], genitocrural n..
- glossopharyngeal n. [CN IX] [TA] ninth cranial n. that emerges from the rostral end of the medulla and passes through the jugular foramen to supply sensation including taste to the pharynx and posterior third of the tongue; it also carries somatic motor fibers to the stylopharyngeus muscle and secretomotor presynaptic parasympathetic fibers to the otic ganglion for innervation of the parotid gland. SYN: nervus glossopharyngeus [CN IX] [TA], ninth cranial n. [CN IX].
- great auricular n. [TA] arises as a branch of the cervical plexus, conveying fibers from the ventral primary rami of the second and third cervical spinal nerves; supplies the skin of part of the auricle, adjacent portion of the scalp, and that overlying the angle of the jaw; it also innervates the parotid sheath, conveying from it the pain fibers stimulated by stretching of the sheath during parotitis (mumps). SYN: nervus auricularis magnus [TA].
- greater occipital n. [TA] medial branch of the dorsal primary ramus of the second cervical n.; sends branches to the semispinalis capitis and multifidus cervicis, but is mainly sensory, supplying the back part of the scalp, meningeal branches to the posterior cranial fossa, and pain and proprioceptive branches to the first cervical n. for the suboccipital muscles. SYN: nervus occipitalis major [TA].
- greater palatine n. [TA] a branch of the pterygopalatine ganglion that passes inferiorly through the greater palatine canal to supply the mucosa and glands of the hard palate, and the anterior part of the soft palate. SYN: nervus palatinus major [TA].
- greater petrosal n. [TA] a branch from the genu of the facial n. exiting via the hiatus of the facial canal and running in a groove on the anterior surface of the petrous part of the temporal bone beside the foramen lacerum to join the deep petrosal n., thus forming the n. of the pterygoid canal, which passes through the pterygoid canal to reach the pterygopalatine ganglion. SYN: nervus petrosus major [TA], parasympathetic root of pterygopalatine ganglion, greater superficial petrosal n..
- greater splanchnic n. [TA] uppermost of the abdominopelvic splanchnic that arises from the fifth or sixth to the ninth or tenth thoracic sympathetic ganglia in the thorax and passes inferiorly along the bodies of the thoracic vertebrae, penetrating the diaphragm to join the celiac plexus; conveys presynaptic sympathetic fibers to the celiac ganglia and visceral afferent fibers from the celiac plexus. SYN: nervus splanchnicus major [TA].
- hemorrhoidal nerves See superior rectal (nervous) plexus, middle rectal (nervous) plexus, inferior anal nerves.
- hypogastric n. [TA] one of the two n. trunks (right and left) that lead from the superior hypogastric plexus (presacral n.) into the pelvis to join the inferior hypogastric plexuses. SYN: nervus hypogastricus [TA].
- hypoglossal n. [CN XII] [TA] arises from an oblong nucleus in the medulla and emerges by several root filaments between the pyramid and the olive via the preolivary groove; it passes through the hypoglossal canal, then courses downward and forward to supply the intrinsic and four of five extrinsic muscles of the tongue. SYN: nervus hypoglossus [CN XII] [TA], twelfth cranial n. [CN XII].
- iliohypogastric n. [TA] terminal branch, with ilioinguinal n., of the first lumbar n.; it supplies the abdominal muscles and the skin of the lower part of the anterior abdominal wall. SYN: nervus iliohypogastricus [TA].
- ilioinguinal n. [TA] terminal branch, with the iliohypogastric n., the first lumbar n., passes through the inguinal canal and superficial inguinal ring to supply the skin of the upper medial thigh, mons pubis, and scrotum or labia majora. SYN: nervus ilioinguinalis [TA].
- inferior alveolar n. [TA] one of the terminal branches of the mandibular, it enters the mandibular canal to be distributed to the lower teeth, periosteum, and gingiva of the mandible; a branch, the mental n., passes through the mental foramen to supply the skin and mucosa of the lower lip and chin. SYN: nervus alveolaris inferior [TA], inferior dental n..
- inferior anal nerves [TA] several branches of the pudendal n. that pass to the external anal sphincter anoderm and skin of the anal region. SYN: nervi anales inferiores [TA], inferior rectal nerves, nervi rectales inferiores, inferior hemorrhoidal nerves.
- inferior cervical cardiac n. [TA] a n. passing from the stellate ganglion to the cardiac plexus. SYN: nervus cardiacus cervicalis inferior [TA].
- inferior clunial nerves [TA] branches of the posterior femoral cutaneous n. emerging from beneath the inferior border of the gluteus maximus to supply the skin of the lower half of the gluteal region. SYN: nervi clunium inferiores [TA].
- inferior gluteal n. [TA] arises as a branch of the sacral plexus, conveying fibers from the fifth lumbar and first and second sacral nerves, and supplies the gluteus maximus muscle. It is subject to injury by compression and ischemia in sedentary individuals, resulting in difficulty in rising from a sitting position and difficulty climbing stairs. SYN: nervus gluteus inferior [TA].
- inferior laryngeal n. [TA] the terminal branch of the recurrent laryngeal n. as the latter passes deep to the inferior pharyngeal constrictor; it supplies the laryngeal mucosa inferior to the vocal folds and all laryngeal muscles except the cricothyroid. SYN: nervus laryngeus inferior [TA].
- inferior lateral cutaneous n. of arm [TA] cutaneous branch of the radial n. supplying the skin of the lower lateral aspect of the arm; it frequently arises as a branch of the posterior antebrachial n.. SYN: nervus cutaneus brachii lateralis inferior [TA], inferior lateral brachial cutaneous n..
- infraorbital n. [TA] the continuation of the maxillary n. [CN V2] after it has traversed the pterygopalatine fossa and enters the orbit, via the infraorbital fissure, it is then transmitted by the infraorbital canal to reach the face; it supplies the mucosa of the maxillary sinus, the upper incisors, canine and premolars, the upper gums, the inferior eyelid and conjunctiva, part of the nose, and the superior lip. SYN: nervus infraorbitalis [TA].
- infratrochlear n. [TA] a terminal branch of the nasociliary n. running beneath the pulley of the superior oblique muscle to the front of the orbit, and supplying the skin of the eyelids and root of the nose. SYN: nervus infratrochlearis [TA].
- intercarotid n. SYN: carotid branch of glossopharyngeal n. (CN IX).
- intercostal nerves [TA] ventral primary rami of thoracic nerves [T1–T11]. SYN: nervi intercostales [TA].
- intercostobrachial nerves [TA] lateral cutaneous branches of the second and third intercostal nerves that pass to the skin of the medial side of the arm. SYN: nervi intercostobrachiales [TA], intercostohumeral nerves.
- intercostohumeral nerves SYN: intercostobrachial nerves.
- intermediary n. SYN: intermediate n..
- intermediate n. [TA] a root of the facial n. containing sensory fibers for taste from the anterior 2/3 of tongue whose cell bodies are located in the geniculate ganglion and presynaptic parasympathetic autonomic fibers whose cell bodies are located in the superior salivatory nucleus, i.e., the fibers are eventually conveyed via the chorda tympani branch of the facial n. to the lingual n.. SYN: nervus intermedius [TA], intermediary n., portio intermedia, Wrisberg n. (2).
- intermediate dorsal cutaneous n. [TA] the lateral terminal branch of the superficial fibular (peroneal) n., supplying the dorsum of the foot and dorsal digital nerves to the toes (except for adjacent parts of great and second toes). SYN: nervus cutaneus dorsalis intermedius [TA].
- intermediate supraclavicular n. [TA] one of several nerves arising from the C-3–C-4 part of the cervical plexus that run across the top of the shoulder and pass down across the shaft of the clavicle to supply the skin of the top of the shoulder and in the infraclavicular region. SYN: nervus supraclavicularis intermedius [TA], middle supraclavicular n..
- internal carotid n. [TA] the cephalic arterial ramus conveying postsynaptic sympathetic fibers from the superior cervical ganglion to the internal carotid artery to form the internal carotid plexus. SYN: nervus caroticus internus [TA].
- jugular n. [TA] a communicating branch between the superior cervical ganglion of the sympathetic n., the superior ganglion of the vagus n., and the inferior ganglion of the glossopharyngeal n.. SYN: nervus jugularis [TA].
- lacrimal n. [TA] a branch of the ophthalmic n. [CN V1] supplying sensory fibers to the lateral part of the upper eyelid, conjunctiva, and lacrimal gland. The secretomotor fibers of the latter were conveyed to the lacrimal n. by the communicating branch of the zygomatic n. (a branch of the maxillary n. [CN V2]. SYN: nervus lacrimalis [TA].
- Latarget n. 1. SYN: superior hypogastric (nervous) plexus. 2. terminal branch of anterior vagal trunk that runs along lesser curvature of the stomach to within a few centimeters of the gastroduodenal junction, but apparently never reaching the pyloric sphincter.
- lateral ampullar n. [TA] a branch of the utriculoampullar n. that supplies the crista ampullaris of the lateral semicircular duct. SYN: nervus ampullaris lateralis [TA].
- lateral cutaneous n. of forearm [TA] the terminal cutaneous branch of the musculocutaneous n. that emerges between biceps brachii and brachialis muscles to supply the skin of the radial side of the forearm. SYN: nervus cutaneus antebrachii lateralis [TA], lateral antebrachial cutaneous n..
- lateral cutaneous n. of thigh [TA] arises from the lumbar plexus, conveying fibers from the second and third lumbar nerves, supplies the skin of the anterolateral and lateral surfaces of the thigh. SYN: nervus cutaneus femoris lateralis [TA], lateral femoral cutaneous n..
- lateral dorsal cutaneous n. [TA] the continuation of the sural n. in the foot, supplying the lateral margin and dorsum. SYN: nervus cutaneus dorsalis lateralis [TA], dorsal lateral cutaneous n..
- lateral pectoral n. [TA] a n. that arises from the lateral cord of the brachial plexus usually passing medial to pectoralis minor to supply the sternoclavicular head of pectoralis major. SYN: nervus pectoralis lateralis [TA], lateral anterior thoracic n..
- lateral plantar n. [TA] one of two terminal branches of the tibial n.; it courses along the lateral side of the sole, dividing into superficial and deep branches; it supplies the skin of the lateral aspect of the sole and the lateral one and one-half toes; it innervates the intrinsic muscles of the plantar part of the foot with the exception of the abductor hallucis and the flexor digitorum brevis; its distribution in the foot is very similar to that of the ulnar n. in the hand. SYN: nervus plantaris lateralis [TA].
- lateral supraclavicular n. [TA] one of several branches of the C-3–C-4 portion of the cervical plexus that descend to the skin over the acromion and deltoid region. SYN: nervus supraclavicularis lateralis [TA], posterior supraclavicular n..
- lateral sural cutaneous n. [TA] it arises from the common fibular (peroneal) in the popliteal space and is distributed to the skin of the inferolateral surface of the calf. SYN: nervus cutaneus surae lateralis [TA], lateral cutaneous n. of calf.
- least splanchnic n. [TA] one of the abdominopelvic splanchnic nerves arising in the thorax and penetrating the diaphragm to supply presynaptic sympathetic fibers for the renal plexus; often combined with the lesser splanchnic n., but occasionally existing as an independent n.. SYN: nervus splanchnicus imus [TA], lowest splanchnic n., smallest splanchnic n..
- lesser occipital n. [TA] arises from cervical plexus, conveying fibers from the ventral primary rami of the second and third cervical nerves; supplies the skin of the posterior surface of the auricle and the adjacent portion of the scalp posterior to the auricle. SYN: nervus occipitalis minor [TA].
- lesser palatine nerves [TA] usually two, these nerves emerge through the lesser palatine foramina and supply the mucosa and glands of the soft palate and uvula; they are branches of the pterygopalatine ganglion and contain postsynaptic parasympathetic and sensory fibers of the maxillary n.. SYN: nervi palatini minores [TA].
- lesser petrosal n. [TA] the parasympathetic root of the otic ganglion, derived from the tympanic plexus; it leaves the tympanic cavity through the canal for the lesser petrosal n. and passes within the cranium to the sphenopetrosal fissure, or to the foramen ovale, or to the petrosal foramen through which it descends to reach the otic ganglion; conveys presynaptic parasympathetic fibers from the glossopharyngeal n. concerned with secretomotor innervation of the parotid gland. SYN: nervus petrosus minor [TA], parasympathetic root of otic ganglion, radix parasympathica ganglii otici, lesser superficial petrosal n..
- lesser splanchnic n. [TA] one of the abdominopelvic splanchnic nerves arising in the thorax from the last two thoracic sympathetic ganglia and passing through the diaphragm to the aorticorenal ganglion; conveys presynaptic sympathetic fibers and visceral afferent fibers. SYN: nervus splanchnicus minor [TA].
- lingual n. [TA] one of the branches of the mandibular n. [CN V3], passing medial to the lateral pterygoid muscle, between the medial pterygoid and the mandible, and beneath the mucous membrane of the floor of the mouth to the side of the tongue over the anterior two-thirds of which it is distributed: it supplies also the mucous membrane of the floor of the mouth. It passes close to the lingual side of the roots of the second and third lower molar teeth and is endangered during tooth extractions. SYN: nervus lingualis [TA].
- long ciliary n. [TA] one of two or three branches of the nasociliary n., which bypass the ciliary ganglion, supplying postsynaptic sympathetic fibers for the dilator pupillae muscle and sensory fibers for the ciliary muscles, iris, and cornea. SYN: nervus ciliaris longus [TA].
- long thoracic n. [TA] arises from the fifth, sixth, and seventh cervical nerves (roots of brachial plexus), descends the neck behind the brachial plexus, and is distributed to the serratus anterior muscle; it is somewhat unusual in that it courses on the superficial aspect of the muscle it supplies; its paralysis results in “winged scapula.” SYN: nervus thoracicus longus [TA], Bell respiratory n., external respiratory n. of Bell, posterior thoracic n..
- lowest splanchnic n. least splanchnic n..
- lumbar nerves [L1–L5] five bilaterally paired spinal nerves emerging from the lumbar portion of the spinal cord; the first four nerves enter into the formation of the lumbar plexus, the fourth and fifth into that of the sacral plexus. SYN: nervi lumbales.
- lumbar splanchnic nerves [TA] branches arising from the medial aspect of the lumbar sympathetic trunks that pass anteriorly and medially to convey presynaptic sympathetic fibers to, and visceral afferents from, the celiac, intermesenteric, aortic, and superior hypogastric plexuses. SYN: nervi splanchnici lumbales [TA].
- mandibular n. [CN V3] [TA] the third division of the trigeminal n. formed by the union of sensory fibers from the trigeminal ganglion and the motor root of the trigeminal n. in the foramen ovale, through which the n. emerges; its branches are: meningeal, masseteric, deep temporal, lateral and medial pterygoid, buccal, auriculotemporal, lingual, and inferior alveolar; its sensory fibers are distributed to the auricle, external acoustic meatus, tympanic membrane, temporal region, cheek, skin overlying the mandible (except its angle), anterior 2/3 of tongue, floor of mouth, lower teeth, and gingiva; its motor fibers innervate all the muscles of mastication plus the mylohyoid, anterior belly of the digestive, and the tensores veli palati and tympani. SYN: nervus mandibularis [CN V3] [TA], inferior maxillary n..
- masseteric n. [TA] a muscular branch of the mandibular n. [CN V3] passing through the mandibular notch to the medial surface of the masseter muscle that it supplies and the temporomandibular joint. SYN: nervus massetericus [TA].
- masticator n. SYN: motor root of trigeminal n..
- maxillary n. [CN V2] the second division of the trigeminal n., passing from the trigeminal ganglion in the middle cranial fossa through the foramen rotundum into the pterygopalatine fossa, where it gives off ganglionic branches to the pterygopalatine ganglion and continues forward to give off the zygomatic n. and enter the orbit, where it continues as the infraorbital n.. Its sensory fibers are distributed to the skin and conjunctiva of the lower eyelid, the skin and mucosa of the upper lip and cheek, the palate, upper teeth and gingiva, the maxillary sinus, wings of the nose, and posterior/interior nasal cavity. SYN: nervus maxillaris [CN V2] [TA], superior maxillary n..
- medial clunial nerves [TA] terminal branches of the dorsal primary rami of the sacral nerves, supplying the skin of the midgluteal region. SYN: nervi clunium medii [TA], middle cluneal nerves.
- medial cutaneous n. of arm [TA] arises from the medial cord of the brachial plexus, unites in the axilla with the lateral cutaneous branch of the second intercostal n., and supplies the skin of the medial side of the arm. SYN: nervus cutaneus brachii medialis [TA], medial brachial cutaneous n., lesser internal cutaneous n., Wrisberg n. (1).
- medial cutaneous n. of forearm [TA] arises from the medial cord of the brachial plexus, passes downward in company with the brachial artery and then the basilic vein, and supplies the skin of the anterior and ulnar surfaces of the forearm. SYN: nervus cutaneus antebrachii medialis [TA], medial antebrachial cutaneous n..
- medial cutaneous n. of leg [TA] branches of saphenous n. distributed to the skin of the medial side of the leg. SYN: rami cutanei cruris mediales nervi sapheni [TA], medial crural cutaneous n., medial crural cutaneous branches of saphenous n..
- medial dorsal cutaneous n. [TA] the medial terminal branch of the superficial fibular (peroneal) n., supplying the dorsum of the foot and dorsal nerves to the toes (except adjacent sides of great and second toes). SYN: nervus cutaneus dorsalis medialis [TA], dorsal medial cutaneous n..
- medial pectoral n. [TA] a n. that arises from the medial cord of the brachial plexus to supply the pectoral muscles; usually pierces pectoralis minor, then continues to supply mainly the sternocostal portion of pectoralis major. SYN: nervus pectoralis medialis [TA], medial anterior thoracic n..
- medial plantar n. [TA] one of the two terminal branches of the tibial n.; it courses along the medial aspect of the sole to supply the abductor hallucis and flexor digitorum brevis and, by way of common and proper digital branches, to innervate the skin of the medial part of the foot and medial three and one-half toes. SYN: nervus plantaris medialis [TA].
- medial supraclavicular n. [TA] one of several nerves arising from the C3–C4 loop of the cervical plexus that supply the skin over the medial end of the clavicle and upper medial part of the thorax. SYN: nervus supraclavicularis medialis [TA], anterior supraclavicular n..
- medial sural cutaneous n. [TA] arises from the tibial n. in the popliteal space, passes down the calf between the two heads of the gastrocnemius and unites in the middle of the leg with the communicating branch of the common peroneal to form the sural n., distributed to the skin of the distal and lateral surfaces of the leg and ankle. SYN: nervus cutaneus surae medialis [TA], popliteal communicating n., tibial communicating n..
- median n. [TA] formed by the union of medial and lateral roots from the medial and lateral cords of the brachial plexus, respectively; it supplies all the muscles in the anterior compartment of the forearm with the exception of the flexor carpi ulnaris and ulnar half of the flexor digitorum profundus; it passes through the carpal tunnel to supply the thenar muscles (except adductor pollicis and the deep head of flexor pollicis brevis) via its recurrent thenar branch; its sensory fibers are distributed to the skin of the palmar and distal dorsal aspects of the radial three and one-half digits and adjacent palm. The median n. is most commonly injured through compression in carpal tunnel syndrome, resulting in a loss of ability to oppose the thumb (“ape hand”) and loss of sensation over the radial portion of the hand. SYN: nervus medianus [TA].
- mental n. [TA] a branch of the inferior alveolar n., arising in the mandibular canal and passing through the mental foramen to the chin and lower lip. SYN: nervus mentalis [TA].
- middle cervical cardiac n. [TA] one of the cardiopulmonary splanchnic nerves conveying postsynaptic sympathetic fibers running downward, from the middle cervical ganglion along the subclavian artery (on the left) or the brachiocephalic (on the right side) to join the cardiac plexus. SYN: nervus cardiacus cervicalis medius [TA].
- motor n. [TA] a n. composed mostly or entirely of efferent (motor) n. fibers conveying impulses that excites muscular contraction; motor nerves in the autonomic nervous system also elicit secretions from glandular epithelia.
- musculocutaneous n. [TA] arises from lateral cord of the brachial plexus, passes through the coracobrachialis muscle, and then downward between the brachialis and biceps, supplying these three muscles and being continued distally as the lateral cutaneous n. of the forearm. SYN: nervus musculocutaneus [TA].
- musculospiral n. SYN: radial n..
- myelinated n. a peripheral n. whose axons are surrounded by layers of Schwann cell membranes that form the myelin sheath; also called medullated nerves.
- n. to mylohyoid [TA] a small branch of the inferior alveolar n. given off posteriorly just before the n. enters the mandibular foramen, distributed to the anterior belly of the digastric muscle and to the mylohyoid muscle. SYN: nervus mylohyoideus [TA], mylohyoid n..
- nasal n. SYN: nasociliary n..
- nasociliary n. [TA] a branch of the ophthalmic n. [CN V1]in the superior orbital fissure, passing through the orbit, giving rise to the communicating branch to the ciliary ganglion, the long ciliary nerves, the posterior and anterior ethmoidal nerves, and terminating as the infratrochlear and nasal branches, which supply the mucous membrane of the nose, the skin of the tip of the nose, and the conjunctiva. SYN: nervus nasociliaris [TA], nasal n..
- nasopalatine n. [TA] a branch from the pterygopalatine ganglion, passing through the sphenopalatine foramen, crossing to and then down the nasal septum, and through the incisive foramen to supply the mucous membrane of the hard palate. SYN: nervus nasopalatinus [TA].
- ninth cranial n. [CN IX] SYN: glossopharyngeal n. [CN IX].
- obturator n. [TA] arises from the lumbar plexus, conveying fibers from the second, third, and fourth lumbar nerves in the psoas muscle, crosses the brim of the pelvis, and enters the thigh through the obturator canal; it supplies muscles of the medial compartment of the thigh (adductors of thigh at the hip joint) and terminates as the cutaneous branch of the obturator n., supplying a small area of medial thigh above knee. SYN: nervus obturatorius [TA].
- oculomotor n. [CN III] [TA] the third cranial n., it supplies all the extrinsic muscles of the eye, except the lateral rectus and superior oblique; it also supplies the levator palpebrae superioris and conveys presynaptic parasympathetic fibers to the ciliary ganglion for innervation of the ciliary muscle and sphincter pupillae; its origin is in the midbrain below the cerebral aqueduct; it emerges from the brain in the interpeduncular fossa, pierces the dura mater to the side of the posterior clinoid process, passes in the lateral wall of the cavernous sinus, and enters the orbit through the superior orbital fissure. SYN: nervus oculomotorius [CN III] [TA], motor oculi, oculomotorius, third cranial n. [CN III].
- olfactory nerves [CN I] [TA] collective term denoting the numerous olfactory filaments: slender fascicles each composed of the thin, unmyelinated axons of 8 to 12 of the bipolar olfactory receptor cells in the olfactory portion of the nasal mucosa; the olfactory filaments pass through the cribriform plate of the ethmoid bone and enter the olfactory bulb, where they terminate in synaptic contact with mitral cells, tufted cells, and granule cells. SEE ALSO: olfactory tract. SYN: fila olfactoria [TA], nervus olfactorii [CN I] [TA], first cranial n. [CN I], n. of smell, olfactory fila.
- ophthalmic n. [CN V1] [TA] a branch of the trigeminal n. that passes forward from the trigeminal ganglion in the lateral wall of the cavernous sinus, entering the orbit through the superior orbital fissure; through its branches, frontal, lacrimal, and nasociliary, it supplies sensation to the orbit and its contents, the anterior part of the nasal cavity, and the skin of the nose and forehead. SYN: nervus ophthalmicus [CN V1] [TA].
- optic n. [CN II] [TA] although classified as a cranial n., it is actually an extension of the forebrain; it conveys afferent fibers from the ganglion cells of the retina, it passes out of the orbit through the optic canal to the chiasm, where part of the fibers cross to the opposite side and pass through the optic tract to the geniculate bodies, superior colliculus, and the pretectum. SYN: nervus opticus [CN II] [TA], second cranial n. [CN II].
- pelvic splanchnic nerves [TA] visceral branches from the ventral primary rami of the second, third, and fourth sacral spinal nerves that join the inferior hypogastric plexus to form the pelvic plexuses, to and from which they convey presynaptic parasympathetic and sensory fibers, respectively. SYN: nervi pelvici splanchnici [TA], parasympathetic root of pelvic ganglia, radices parasympathicae gangliorum pelvicorum, nervi erigentes.
- perineal nerves [TA] the superficial terminal branches of the pudendal n., supplying most of the muscles of the perineum (deep branch) as well as the skin of that region (superficial branch). SYN: nervi perineales [TA].
- pharyngeal n. [TA] branch of pterygopalatine ganglion passing posteriorly through pharyngeal canal to supply postsynaptic parasympathetic fibers to mucus glands of nasopharynx. SYN: nervus pharyngeus [TA], Bock n., pharyngeal branch of pterygopalatine ganglion, ramus pharyngeus ganglii pterygopalatini.
- phrenic n. [TA] arises from the cervical plexus, chiefly conveying fibers from the fourth cervical n., passes downward in front of the anterior scalene muscle and enters the thorax between the subclavian artery and vein behind the sternoclavicular articulation; it then passes in front of the root of the lung to the diaphragm; it is mainly the motor n. of the diaphragm but sends sensory fibers to the mediastinal parietal pleura, the pericardium, the diaphragmatic pleura and peritoneum, and branches (phrenicoabdominales branches) that communicate with branches from the celiac plexus. SYN: nervus phrenicus [TA].
- pneumogastric n. SYN: vagus n. [CN X].
- posterior ampullar n. [TA] a branch of the vestibular part of the eighth n. that supplies the crista ampullaris of the posterior semicircular duct. SYN: nervus ampullaris posterior [TA].
- posterior auricular n. [TA] the first extracranial branch of the facial n., it passes behind the ear, supplying the auricularis posterior, intrinsic muscles of the auricle and, through its occipital branch, the occipital belly of the occipitofrontalis muscle. SYN: nervus auricularis posterior [TA].
- posterior cutaneous n. of arm [TA] a branch of the radial n. supplying the skin of the posterior surface of the arm. SYN: nervus cutaneus brachii posterior [TA], posterior brachial cutaneous n..
- posterior cutaneous n. of forearm [TA] a branch of the radial n. supplying the skin of the dorsal surface of the forearm. SYN: nervus cutaneus antebrachii posterior [TA], posterior antebrachial cutaneous n..
- posterior cutaneous n. of thigh [TA] arises as a branch of the sacral plexus, conveying fibers from the ventral rami of first three sacral nerves; supplies the skin of the posterior surface of the thigh and of the popliteal region (S1 and S2 component); it gives off a perineal branch (S3 component) that passes to the lateral aspect of the scrotum or labia majora. SYN: nervus cutaneus femoris posterior [TA], posterior femoral cutaneous n., small sciatic n..
- posterior ethmoidal n. [TA] a branch of the nasociliary n. providing sensory innervation to the sphenoidal sinus and the posterior ethmoidal air cells. SYN: nervus ethmoidalis posterior [TA].
- posterior inferior nasal nerves [TA] branches of greater palatine n. to posterior inferior lateral wall of nasal cavity, including posterior aspect of mucosa over posterior portion of inferior nasal concha and meatus; may arise independently from pterygopalatine ganglion. SYN: rami nasales posteriores inferiores nervi palatini majoris [TA], posterior inferior nasal branches of greater palatine n..
- posterior interosseous n. [TA] the terminal portion of the deep branch of the radial n.; arises in the cubital region, penetrating and supplying the supinator and continuing with the posterior interosseous artery to supply all the extensor muscles in the forearm. SYN: nervus interosseus antebrachii posterior [TA], dorsal interosseous n., nervus antebrachii posterior, nervus interosseus dorsalis, nervus interosseus posterior, posterior antebrachial n..
- posterior labial nerves [TA] terminal branches of the superficial perineal n., supplying the skin of the posterior portion of the labia and the vestibule of the vagina, corresponding to the posterior scrotal nerves in the male. SYN: nervi labiales posteriores [TA].
- posterior scrotal nerves [TA] several terminal branches of the superficial perineal n. supplying the skin of the posterior portion of the scrotum, corresponding to the posterior labial nerves in the female. SYN: nervi scrotales posteriores [TA].
- pressor n. an afferent n., stimulation of which excites a reflex vasoconstriction, thereby raising the blood pressure.
- pressoreceptor n. a n. composed of afferent fibers the endings of which are sensitive to increases in mechanical pressure; the term specifically refers to sensory nerves innervating the walls of hollow organs. SYN: baroreceptor n..
- proper palmar digital nerves [TA] the palmar nerves of the digits of the hand derived from common palmar digital nerves; each n. supplies a palmar quadrant of a digit and a part of the dorsal surface of the distal phalanx. SYN: nervi digitales palmares proprii [TA].
- proper plantar digital nerves [TA] the ten nerves derived from the common plantar digital nerves; each n. supplies a plantar quadrant of a toe and part of the dorsal surface of the distal phalanx. SYN: nervi digitales plantares proprii [TA].
- pterygoid n. [TA] one of two motor branches, the nerves to the lateral and medial pterygoid muscles, from the mandibular n., supplying muscles with fibers of the motor root of the trigeminal n.. SYN: nervus pterygoideus [TA].
- n. of pterygoid canal [TA] the n. constituting the parasympathetic and sympathetic root of the pterygopalatine ganglion; it is formed in the region of the foramen lacerum by the union of the greater and deep petrosal nerves and runs through the pterygoid canal to the pterygopalatine fossa. SYN: nervus canalis pterygoidei [TA], facial root, radix facialis, vidian n..
- pudendal n. [TA] branch of the sacral plexus formed by fibers from the ventral primary rami of the second, third, and fourth sacral spinal nerves; it exits the pelvis via the greater sciatic foramen, passes posterior to the sacrospinous ligament, and accompanies the internal pudendal artery, into the perineum via the lesser sciatic foramen; it gives off inferior rectal nerves, then courses through the pudendal canal in the lateral wall of the ischiorectal fossa, terminating as the dorsal n. of the penis or of the clitoris. SYN: nervus pudendus [TA], plexus pudendus nervosus, pudic n..
- radial n. [TA] arises from the posterior cord of the brachial plexus conveying fibers from all roots of the plexus; it curves around the posterior surface of the humerus and passes down to the cubital fossa where it divides into its two terminal branches, the cutaneous superficial branch and the motor deep branch; it supplies the muscles of the posterior compartments of the arm and forearm and overlying skin. The radial n. is most commonly injured by fractures of the middle 1/3 of the humerus, resulting in a loss of extension at the wrist (“wrist drop”). SYN: nervus radialis [TA], musculospiral n..
- recurrent laryngeal n. [TA] a branch of the vagus n. curving upward, on the right side around the root of the subclavian artery, on the left side around the arch of the aorta, then passing superiorly, posterior to the common carotid artery between the trachea and the esophagus to the larynx; it supplies cardiac, tracheal, and esophageal branches and terminates as the inferior laryngeal n.. SYN: nervus laryngeus recurrens [TA], recurrent n..
- recurrent meningeal n. meningeal branches of 1) mandibular, 2) maxillary, 3) ophthalmic, and 4) spinal nerves.
- saccular n. [TA] a branch of the inferior part of the vestibular n. going to the macula of the sacculus. SYN: nervus saccularis [TA].
- sacral splanchnic nerves [TA] branches from the sacral sympathetic trunk that pass to the inferior hypogastric plexus; part of the abdominopelvic (sympathetic) splanchnic nerves, but their specific function is unclear. They tend to be confused with the pelvic splanchnic nerves, which are much more significant structures. SYN: nervi splanchnici sacrales [TA].
- sacral nerves [S1–S5] five nerves issuing from the sacral foramina on either side; the ventral branches of the first three enter into the formation of the sacral plexus, and the last two into the coccygeal plexus. SYN: nervi sacrales [S1–S5].
- saphenous n. [TA] a branch of the femoral, extending from the femoral triangle to the foot, becoming subcutaneous on the medial side of the knee; it supplies cutaneous branches to the skin of the leg and foot, by way of infrapatellar and medial crural branches. SYN: nervus saphenus [TA], internal saphenous n., long saphenous n..
- sciatic n. [TA] arises as the major product of the sacral plexus, exits the pelvis via the greater sciatic foramen, and descends in the posterior compartment of the thigh, deep to the long head of biceps femoris n.; at the apex of the popliteal fossa it divides into the common peroneal and tibial nerves, although the two may separate at higher levels. SYN: nervus ischiadicus [TA], great sciatic n., nervus sciaticus.
- second cranial n. [CN II] SYN: optic n. [CN II].
- secretomotor n. SYN: secretory n..
- secretory n. a n. conveying impulses that excite functional activity in a gland. SYN: secretomotor n..
- sensory n. an afferent n. conveying impulses that are processed by the central nervous system so as to become part of the organism's perception of self and its environment.
- short ciliary n. [TA] one of a number of branches passing from the ciliary ganglion to the eyeball, supplying the ciliary muscles, iris, and tunics of the eyeball. SYN: nervus ciliaris brevis [TA].
- smallest splanchnic n. SYN: least splanchnic n..
- somatic n. one of the nerves of parietal sensation or voluntary motion, as distinguished from the visceral sensory, involuntary motor, and secretory nerves.
- spinal nerves [TA] the nerves emerging from the spinal cord; there are 31 pairs, each arising from the cord by rootlets that converge to form two roots, anterior (ventral or motor) and posterior (dorsal or sensory); the latter type is provided with a circumscribed enlargement, the spinal (dorsal root) ganglion; the two roots unite in the intervertebral foramen, and the mixed spinal n. almost immediately divides again into anterior and posterior (primary) rami, the former supplying the anterolateral trunk and the limbs, the latter the true muscles and overlying skin of the back. SYN: nervi spinales [TA].
- splanchnic n. one of the nerves supplying the viscera. There are three groups of splanchnic nerves: cardiopulmonary splanchnic nerves that convey postsynaptic sympathetic fibers to thoracic viscera; abdominopelvic nerves that convey presynpatic sympathetic fibers to the sympathetic ganglia of the abdominopelvic cavity; and pelvic splanchnic nerves that convey presynaptic parasympathetic fibers to the pelvic ganglia. See also entries under the individual listings for the splanchnic nerves mentioned.
- n. to stapedius muscle [TA] a branch of the facial arising in the facial canal and innervating the stapedius muscle. SYN: nervus stapedius [TA].
- statoacoustic n. SYN: vestibulocochlear n. [CN VIII].
- subclavian n. [TA] a branch from the superior trunk of the brachial plexus supplying the subclavius muscle. SYN: nervus subclavius [TA].
- subcostal n. [TA] the ventral ramus of the twelfth thoracic n.; it courses below the last rib paralleling the course of the intercostal nerves superior to it; it supplies parts of the abdominal muscles and gives off cutaneous branches to the skin of the lowermost ventrolateral abdominal wall and to the superolateral gluteal region. SYN: nervus subcostalis [TA].
- sublingual n. [TA] a branch of the lingual to the sublingual gland and mucosa of the floor of the mouth. SYN: nervus sublingualis [TA].
- suboccipital n. [TA] dorsal ramus of the first cervical n., passing through the suboccipital triangle and sending branches to the rectus capitis posterior major and minor, obliquus capitis superior and inferior, rectus capitis lateralis, and semispinalis capitis; the first cervical spinal n. is generally considered to have only motor fibers, but the suboccipital n. receives sensory fibers for proprioception via a communicating branch from the second cervical spinal n.. SYN: nervus suboccipitalis [TA].
- subscapular nerves [TA] two branches of the posterior cord of the brachial plexus, an upper and lower, supplying the subscapularis muscle; the lower subscapular n. also supplies the teres major muscle. SYN: nervi subscapulares [TA].
- sudomotor nerves nerves containing autonomic (general visceral efferent–postganglionic) fibers that innervate sweat glands.
- superficial fibular n. [TA] a branch of the common fibular (peroneal) n. that passes downward in the lateral compartment of the leg to supply the fibularis (peroneus) longus and brevis muscles and terminate as the intermediate and medial dorsal cutaneous nerves supplying the skin of the dorsum of the foot and toes (except for adjacent sides of great and second toes). SYN: nervus fibularis superficialis [TA], nervus peroneus superficialis, superficial peroneal n., musculocutaneous n. of leg.
- superior alveolar nerves [TA] three branches (posterior, middle, and anterior) of the maxillary n. (or its continuation as the infraorbital n.) that enter the maxilla to supply the mucosa of the maxillary sinus, upper teeth, and gingiva. SYN: nervi alveolares superiores [TA], superior dental nerves.
- superior cervical cardiac n. [TA] the uppermost of the cardiopulmonary splanchnic nerves that arises from the lower part of the superior cervical ganglion and passes down to form, with branches of the vagus, the cardiac plexus. SYN: nervus cardiacus cervicalis superior [TA].
- superior clunial nerves [TA] terminal branches of the dorsal primary rami of the lumbar nerves, supplying the skin of the upper half of the gluteal region. SYN: nervi clunium superiores [TA].
- superior gluteal n. [TA] arises from sacral plexus, conveying fibers from the fourth and fifth lumbar and first sacral nerves, and supplies the gluteus medius and minimus and tensor fasciae latae muscles (abductors and medial rotators of the hip joint). A lesion of this n. causes the pelvis to drop on the unsupported side when the foot is lifted off the ground (Trendelenburg sign). SYN: nervus gluteus superior [TA].
- superior laryngeal n. [TA] a branch of the vagus n. at the inferior ganglion; at the thyroid cartilage it divides into two branches: the internal laryngeal n., a sensory branch that supplies the mucous membrane of the larynx superior to the vocal folds, and the external laryngeal n., a motor branch that supplies the inferior pharyngeal constrictor and the cricothyroid muscle. SYN: nervus laryngeus superior [TA].
- supraorbital n. [TA] a branch of the frontal n. leaving the orbit through the supraorbital foramen or notch and dividing into branches distributed to the forehead and scalp, upper eyelid, and frontal sinus. SYN: nervus supraorbitalis [TA].
- suprascapular n. [TA] arises from the upper trunk of the brachial plexus (fifth and sixth cervical spinal nerves), passes downward parallel to the cords of the brachial plexus, then through the scapular notch, supplying the supraspinatus and infraspinatus muscles, and also sending branches to the shoulder joint. It is vulnerable to injury in fractures of the middle 1/3 of the clavicle; a lesion of the suprascapular n. results in a loss of lateral rotation at the shoulder so that when relaxed the limb rotates medially (waiter's tip position); ability to initiate abduction is also affected. SYN: nervus suprascapularis [TA].
- supratrochlear n. [TA] a branch of the frontal n. supplying the medial part of the upper eyelid, the central part of the skin of the forehead, and the root of the nose. SYN: nervus supratrochlearis [TA].
- sural n. [TA] formed by the union of the medial sural cutaneous from the tibial and the peroneal communicating branch of the common peroneal n., usually about the middle of the calf, although this is highly variable; thence it accompanies the small saphenous vein around the lateral malleolus to the dorsum of the foot as the lateral dorsal cutaneous n.. SYN: nervus suralis [TA], external saphenous n., short saphenous n..
- temporomandibular n. SYN: zygomatic n..
- n. to tensor tympani (muscle) [TA] a branch of the mandibular n. conveying fibers from the motor root of the trigeminal n. that pass through the otic ganglion without synapse to supply the tensor tympani muscle. SYN: nervus musculi tensoris tympani [TA].
- n. to tensor veli palatini (muscle) [TA] a branch of the mandibular n. conveying fibers from the motor root of the trigeminal n. that pass through the otic ganglion without synapse to supply the tensor veli palatini muscle. SYN: nervus musculi tensoris veli palatini [TA].
- tentorial n. [TA] the meningeal branch arising in a recurrent fashion from the intracranial portion of the ophthalmic n. supplying the tentorium cerebelli and supratentorial falx cerebri. SYN: ramus meningeus recurrens nervi ophthalmici [TA], ramus tentorii, nervus tentorii.
- terminal n. [TA] delicate plexiform n. strands passing parallel and medial to the olfactory tracts, distributing peripherally with the olfactory nerves and passing centrally into the anterior perforated substance; they are considered to have an autonomic function, but the exact nature of this is unknown. SYN: nervus terminalis [TA].
- third cranial n. [CN III] SYN: oculomotor n. [CN III].
- third occipital n. [TA] medial branch of the dorsal primary ramus of the third cervical n.; this is usually joined with the greater occipital, but may exist as an independent n. supplying cutaneous branches to the scalp and nucha. SYN: nervus occipitalis tertius [TA].
- thoracic splanchnic nerves splanchnic nerves arising from the thoracic portion of the sympathetic trunks; the upper thoracic splanchnic nerves (from T1 to T4 or 5) pass to viscera above the diaphragm (mainly heart, lungs, and esophagus) and so are cardiopulmonary splanchnic nerves; the lower thoracic splanchnic nerves form the greater, lesser, and lowest splanchnic nerves and supply viscera below the level of the diaphragm, and so are abdominopelvic splanchnic nerves.
- thoracic nerves [T1–T12] [TA] twelve nerves on each side, mixed motor and sensory, supplying the muscles and skin of the thoracic and abdominal walls. SYN: nervi thoracici [T1–12].
- thoracoabdominal nerves the ventral primary rami of spinal nerves T7–T11 (seventh to eleventh intercostal nerves), which supply the abdominal as well as the thoracic wall; innervate intercostal, subcostal, serratus posterior inferior, transversus abdominis, external and internal oblique, and rectus abdominis muscles, and provide sensory branches to the periphery of the diaphragm, and parietal pleura and peritoneum. SYN: anterior cutaneous nerves of abdomen, pectoral and abdominal anterior cutaneous branch of intercostal nerves, rami cutanei anteriores pectoralis et abdominalis nervorum intercostalium, ramus cutaneus anterior (pectoralis et abdominalis) nervorum thoracicorum.
- thoracodorsal n. [TA] arises from the posterior cord of the brachial plexus; it contains fibers from the sixth, seventh, and eighth cervical nerves and supplies the latissimus dorsi muscle. SYN: nervus thoracodorsalis [TA], long subscapular n..
- tibial n. [TA] one of the two major divisions of the sciatic n., it courses down the back of the leg to terminate as the medial and lateral plantar nerves in the foot; it supplies the hamstring muscles, the muscles of the back of the leg (the dorsiflexors and invertors of the foot), and the plantar aspect of the foot, as well as the skin on the back of the leg and sole of the foot. SYN: nervus tibialis [TA], medial popliteal n..
- transverse cervical n. [TA] a branch of the cervical plexus that supplies the skin over the anterior triangle of the neck. SYN: nervus transversus colli [TA], nervus transversus cervicalis, cutaneous cervical n., nervus cervicalis superficialis, superficial cervical n., transverse n. of neck.
- trifacial n. SYN: trigeminal n. [CN V].
- trigeminal n. [CN V] [TA] the chief sensory n. of the face and the motor n. of the muscles of mastication; its nuclei are in the mesencephalon and in the pons and medulla oblongata extending down into the cervical portion of the spinal cord; it emerges by two roots, sensory and motor, from the lateral portion of the surface of the pons, and enters a cavity of the dura mater, the trigeminal cave, at the apex of the petrous portion of the temporal bone, where the sensory root expands to form the trigeminal ganglion; from there the three divisions (ophthalmic [CN V1], maxillary [CN V2], and mandibular [CN V3] nerves) arise. SYN: nervus trigeminus [CN V] [TA], fifth cranial n. [CN V], trifacial n..
- trochlear n. [CN IV] [TA] supplies the superior oblique muscle of the eye; its origin is in the midbrain below the cerebral aqueduct, and its fibers decussate in the superior medullary velum, and emerge from the brain at the side of the frenulum, the only cranial n. to arise from the dorsal aspect of the brainstem; it therefore has the longest intracranial course, entering the dura in the free edge of the tentorium, close to the posterior clinoid process, and passing in the lateral wall of the cavernous sinus to enter the orbit through the superior orbital fissure. SYN: nervus trochlearis [CN IV] [TA], fourth cranial n. [CN IV], pathetic n..
- twelfth cranial n. [CN XII] SYN: hypoglossal n. [CN XII].
- tympanic n. [TA] a n. from the inferior ganglion of the glossopharyngeal n., passing through the tympanic canaliculus to the tympanic cavity, forming there the tympanic plexus that supplies the mucous membrane of the tympanic cavity, mastoid cells, and auditory tube; presynaptic parasympathetic fibers also pass through the tympanic n. via the lesser superficial petrosal n. to the otic ganglion, where they synapse with postsynaptic fibers that continue to supply the parotid gland. SYN: nervus tympanicus [TA], Andersch n., Jacobson n..
- ulnar n. [TA] arises from the medial cord of the brachial plexus conveying fibers mainly from the C8 and T1 nerves; it passes down the arm, behind the medial epicondyle of the humerus, and down the ulnar side of the anterior compartment of the forearm to the hand; it gives off muscular branches in the forearm to the flexor carpi ulnaris muscle and the ulnar portion of flexor digitorum profundus and supplies the hypothenar, interosseous, medial lumbricals, adductor pollicis, and deep head of flexor hallucis brevis, and the intrinsic muscles of the hand and the skin of the small finger and medial side of the ring finger and adjacent portions of the palm of the hand. The ulnar n. is most vulnerable to injury where it passes subcutaneously behind the medial epicondyle of the humerus. Mild injury here produces “crazy bone” sensation. An ulnar n. lesion here results in loss of flexion of metacarpophalangeal joints and of extension at the interphalangeal joints (“claw hand”). SYN: nervus ulnaris [TA], cubital n..
- unmyelinated n. a n. made up largely, or exclusively, of unmyelinated fibers; a n. composed of axons having no myelin covering, but lying in troughs in Schwann cells; a slow conducting n..
- upper lateral cutaneous n. of arm [TA] the terminal branch of the axillary n. supplying the skin over the lower portion of the deltoid and for a distance below its insertion. SYN: nervus cutaneus brachii lateralis superior [TA], superior lateral brachial cutaneous n..
- upper subscapular n. subscapular nerves.
- upper thoracic splanchnic nerves SYN: thoracic cardiac branches of thoracic ganglia, under branch.
- utricular n. [TA] a branch of the utriculoampullar n., supplying the macula of the utricle. SYN: nervus utricularis [TA].
- utriculoampullar n. [TA] a division of the vestibular part of the eighth cranial n.; it gives off branches to the macula of the utricle (utricular n.) and to the cristae of the ampullae of the anterior and lateral semicircular ducts (anterior and lateral ampullary nerves). SYN: nervus utriculoampullaris [TA].
- vaginal nerves [TA] several nerves passing from the uterovaginal plexus to the vagina. SYN: nervi vaginales [TA].
- vagus n. [CN X] [TA] a mixed n. that arises by numerous small roots from the side of the medulla oblongata, between the glossopharyngeal above and the accessory below; it leaves the cranial cavity by the jugular foramen and passes down to supply the pharynx, larynx, trachea, lungs, heart, and the gastrointestinal tract as far as the left colic (splenic) flexure; the only cranial n. that does not arise from the brain, but is classified as such because it exits from the cranium. SYN: nervus vagus [CN X] [TA], pneumogastric n., tenth cranial n. [CN X], vagus.
- vascular nerves [TA] a small n. filament that supplies the wall of a blood vessel. SYN: nervi vascularorum [TA].
- vertebral n. a branch from the stellate ganglion that ascends along the vertebral artery to the level of the axis or atlas, giving branches to the cervical nerves and meninges. SYN: nervus vertebralis.
- vestibular n. [TA] the part of the vestibulocochlear n. [CN VIII] peripheral to the vestibular root; it is composed of the central processes of bipolar neurons that have their terminals of their peripheral processes on the hair cells in the ampullae of the semicircular ducts and the maculae of the saccule and utricle, and cell bodies of the vestibular ganglion. SEE ALSO: vestibular root. SYN: nervus vestibularis [TA], pars vestibularis nervi vestibulocochlearis, superior part of vestibulocochlear n., vestibular part of vestibulocochlear n..
- vestibulocochlear n. [CN VIII] [TA] a composite sensory n. innervating the receptor cells of the membranous labyrinth; it consists of two major, anatomically and functionally distinct components, each of which have different central connections: the vestibular n. and the cochlear n.. SYN: nervus vestibulocochlearis [CN VIII] [TA], eighth cranial n. [CN VIII], eighth n., nervus acusticus, nervus octavus, nervus statoacusticus, octavus, statoacoustic n..
- zygomatic n. [TA] a branch of the maxillary n. [CN V2] in the inferior orbital fissure through which it passes; it gives rise to two sensory branches, the zygomaticotemporal and zygomaticofacial, which supply the skin of the temporal and zygomatic regions and is continued as the communicating branch of the lacrimal n. with the zygomatic n.. SYN: nervus zygomaticus [TA], orbital n., temporomandibular n..
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nerve 'nərv n
1) any of the filamentous bands of nervous tissue that connect parts of the nervous system with the other organs, conduct nervous impulses, and are made up of axons and dendrites together with protective and supportive structures and that for the larger nerves have the fibers gathered into funiculi surrounded by a perineurium and the funiculi enclosed in a common epineurium
2) nerves pl a state or condition of nervous agitation or irritability
3) the sensitive pulp of a tooth
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n.
a bundle of conducting nerve fibre that transmit impulses from the brain or spinal cord to the muscles and glands (motor nerves) or inwards from the sense organs to the brain and spinal cord (sensory nerves). Most large nerves are mixed nerves, containing both motor and sensory nerve fibres running to and from a particular region of the body.
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(nurv) [L. nervus] a cordlike structure made up of a collection of fibers that convey impulses between a part of the central nervous system and some other region of the body. A nerve consists of a connective tissue sheath (epineurium) enclosing bundles of fibers (funiculi or fasciculi); each bundle is in turn surrounded by its own sheath of connective tissue (perineurium), the inner surface of which is formed by a membrane of flattened mesothelial cells. Very small nerves may consist of only one funiculus derived from the parent nerve. Within each such bundle, the individual nerve fibers, which are microscopic in size, are surrounded by interstitial connective tissue (endoneurium). An individual nerve fiber (an axon with its covering sheath) consists of formed elements in a matrix of protoplasm (axoplasm), the entire structure being enclosed in a thin membrane (axolemma). Each nerve fiber is enclosed by a cellular sheath (neurilemma), from which it may or may not be separated by a lipid layer (myelin sheath) derived from neurilemmal cells. In official terminology called nervus.
PLATE 33 SUPERFICIAL NERVES AND MUSCLES OF THE HEAD AND NECK
PLATE 34 DEEP NERVES SHOWN IN RELATION TO BONES OF THE FACE
PLATE 35 DEEP NERVES OF THE NECK, AXILLA, AND UPPER THORAX
PLATE 36 DEEP NERVES OF THE LOWER TRUNK
PLATE 37 NERVES OF THE UPPER LIMB
PLATE 38 NERVES OF THE LOWER LIMB
PLATE 39 STRUCTURE OF NERVE TISSUE
For names and descriptions of specific nerves, see under nervus.
Medical dictionary. 2011.