WordNet

any bundle of nerve fibers running to various organs and tissues of the body (同)nervus
control of your emotions; "this kind of tension is not good for my nerves"

PrepTutorEJDIC

〈C〉『神経』 / 〈C〉《複数形で》『神経過敏』,いらだち / 〈U〉『勇気』,度胸(courage) / 〈U〉《時にa ~》厚かましさ,ずぶとさ;無礼 / 〈C〉葉脈;(昆虫の)翅脈(しみゃく) / 〈人,特に自分〉‘に'力を与える,‘を'元気づける
身体の / 体腔(たいこう)の / 体細胞の

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/02/24 14:05:11」(JST)

wiki en

For the musician known as Somatic, see Hahn Rowe.

The somatic nervous system (SoNS Or voluntary nervous system) is the part of the peripheral nervous system ^[1] associated with the voluntary control of body movements via skeletal muscles. The SoNS consists of efferent nerves responsible for stimulating muscle contraction, including all the non-sensory neurons connected with skeletal muscles and skin.

Parts of Somatic Nervous System

There are forty three segments of nerves in our body and with each segment there is a pair of sensory and motor nerves. In the body, thirty one segments of nerves are in the spinal cord and twelve are in the brain stem.

Besides these, thousands of association nerves are also present in the body.

Thus Somatic Nervous System consists of three parts:

i) Spinal Nerves: They are peripheral nerves that carry sensory information into the spinal cord and motor commands.

ii) Cranial Nerves: They are the nerve fibers which carry information into and out of the brain stem. They include smell, vision, eye, eye muscles, mouth, vision,. Taste, ear, neck, shoulders and tongue.

iii) Association Nerves: These nerves integrate sensory input and motor output numbering thousands.

Nerve signal transmission

The somatic nervous system controls all voluntary muscular systems within the body, with the exception of reflex arcs.

The basic route of nerve signals within the efferent somatic nervous system involves a sequence that begins in the upper cell bodies of motor neurons (upper motor neurons) within the precentral gyrus (which approximates the primary motor cortex). Stimuli from the precentral gyrus are transmitted from upper motor neurons and down the corticospinal tract, via axons to control skeletal (voluntary) muscles. These stimuli are conveyed from upper motor neurons through the ventral horn of the spinal cord, and across synapses to be received by the sensory receptors of alpha motor neurons (large lower motor neurons) of the brainstem and spinal cord.

Upper motor neurons release a neurotransmitter, acetylcholine, from their axon terminal knobs, which are received by nicotinic receptors of the alpha motor neurons. In turn, alpha motor neurons relay the stimuli received down their axons via the ventral root of the spinal cord. These signals then proceed to the neuromuscular junctions of skeletal muscles.

From there, acetylcholine is released from the axon terminal knobs of alpha motor neurons and received by postsynaptic receptors (Nicotinic acetylcholine receptors) of muscles, thereby relaying the stimulus to contract muscle fibers.

Vertebrate and invertebrate differences

In invertebrates, depending on the neurotransmitter released and the type of receptor it binds, the response in the muscle fiber could either be excitatory or inhibitory. For vertebrates, however, the response of a muscle fiber to a neurotransmitter (always acetylcholine (ACh)) can only be excitatory.

Reflex arcs

A reflex arc is a neural circuit that creates a more or less automatic link between a sensory input and a specific motor output. Reflex circuits vary in complexity—the simplest spinal reflexes are mediated by a three-element chain, beginning with sensory neurons which activate interneurons in the spinal cord, which then activate motor neurons. Some reflex responses, such as withdrawing the hand after touching a hot surface, are protective, but others, such as the patellar reflex "knee jerk" activated by tapping the patellar tendon, contribute to ordinary behaviour.

References

^ "somatic nervous system" at Dorland's Medical Dictionary

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 身体化：疫学、病因、臨床的特徴、医学的評価、および診断 somatization epidemiology pathogenesis clinical features medical evaluation and diagnosis
2. 身体化：治療および予後 somatization treatment and prognosis
3. 医学的に原因不明の症状に対するプライマリケア管理 primary care management of medically unexplained symptoms
4. 女性における慢性骨盤痛の原因 causes of chronic pelvic pain in women
5. ライム病：小児における臨床症状 lyme disease clinical manifestations in children

English Journal

Histone acetylation and Histone deacetylation in neuropathic pain: An Unresolved puzzle?

Khangura RK1, Bali A2, Jaggi AS3, Singh N2.
European journal of pharmacology.Eur J Pharmacol.2016 Dec 2. pii: S0014-2999(16)30771-3. doi: 10.1016/j.ejphar.2016.12.001. [Epub ahead of print]
Chronic pain is broadly classified into somatic, visceral or neuropathic pain depending upon the location and extent of pain perception. Evidences from different animal studies suggest that inflammatory or neuropathic pain is associated with altered acetylation and deacetylation of histone proteins,
PMID 27916557

Urological Outcome of the Xiao Procedure in Children with Myelomeningocele and Lipomyelomeningocele Undergoing Spinal Cord Detethering.

Tuite GF1, Homsy Y2, Polsky EG2, Reilly MA3, Carey CM4, Winesett SP5, Rodriguez LF4, Storrs BB4, Gaskill SJ6, Tetreault LL7, Martinez DG7, Amankwah EK7.
The Journal of urology.J Urol.2016 Dec;196(6):1735-1740. doi: 10.1016/j.juro.2016.05.111. Epub 2016 Jun 8.
PURPOSE: Although previous studies have revealed high success rates (70% to 85%) after an intradural somatic-to-autonomic nerve transfer procedure in children with spinal dysraphism, no study has had a control group or blinded observers. We report a rigorously designed study to investigate the effec
PMID 27288694

Low Somatic Sodium Conductance Enhances Action Potential Precision in Time-Coding Auditory Neurons.

Yang Y1, Ramamurthy B2, Neef A3, Xu-Friedman MA4.
The Journal of neuroscience : the official journal of the Society for Neuroscience.J Neurosci.2016 Nov 23;36(47):11999-12009.
Auditory nerve fibers encode sounds in the precise timing of action potentials (APs), which is used for such computations as sound localization. Timing information is relayed through several cell types in the auditory brainstem that share an unusual property: their APs are not overshooting, suggesti
PMID 27881784

Japanese Journal

機能性身体症候群(FSS)患者における,ストレス前唾液アミラーゼとアレキシサイミア傾向との関係

木場律志,神原憲治,山本和美 [他],伴郁美,岡裕子,加藤文恵,福永幹彦
心身医学 53(7), 670-681, 2013-07-01
… 目的:機能性身体症候群(functional somatic syndrome:FSS)患者の予期緊張を,唾液アミラーゼで評価し,心理指標との関係を検討した.方法:FSS患者27名と,コントロール22名のストレス負荷前の唾液アミラーゼ測定と,気分,不安,抑うつ,アレキシサイミア傾向を測る心理検査を行った.結果:唾液アミラーゼ値はコントロールよりFSS患者で高く,コントロールで一過性の抑うつとアレキシサイミア傾向が,FSS患者で緊張,不安,持続的な抑うつが …
NAID 110009615301

Analysis of Somatosensory Evoked Potential for Mechanical Stimuli Mapped on Realistic-Shaped Cortical Surface

Hori Junichi,Kishi Takayoshi,Kon Ryuta
IEEJ Transactions on Electronics, Information and Systems 133(1), 169-176, 2013
… In clinical situations, the objective evaluation of somatic sensations is expected without a patient's subjective opinions to reduce social problems such as those related to lawsuits for nerve injuries or malingering. …
NAID 130003363181

機械刺激および温度刺激による体性感覚の客観評価(BCI/BMIとその周辺,一般)

近竜太,堀潤一
電子情報通信学会技術研究報告. MBE, MEとバイオサイバネティックス 112(297), 37-42, 2012-11-09
臨床現場において,顎関節症等の疼痛患者の処置や神経損傷による医療訴訟が社会問題となっており,体性感覚の客観評価が望まれている.本研究では,ピエゾ型触覚刺激装置で機械刺激を与えた場合の脳内電気活動を解析した.実形状脳皮質電位イメージングによって解析した結果,刺激部位の違いを識別できた.また,ペルチェ型温度刺激装置で手に熱刺激を与えた場合,脳波に対して,時間周波数解析を行った.結果,温度一定時と温度変 …
NAID 110009642327