musculus sphincter

括約筋

WordNet

1. an external ring of striated muscle surrounding the anus
2. the smooth muscle sphincter of the main pancreatic duct
3. the smooth muscle sphincter of the common bile duct
4. a ring of muscle that contracts to close an opening (同)anatomical sphincter, sphincter_muscle

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1. 括約筋(かつやくきん)

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/09/29 19:39:19」(JST)

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Sphincter
Anatomical terms of muscle

A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 9000 types in the human body, some microscopically small, in particular the millions of precapillary sphincters. Sphincters relax at death, often releasing fluids.

Functions

Sphincters control the passage of liquids and solids. This is evident, for example, in the blowholes of numerous marine mammals.

Many sphincters are used every day in the normal course of digestion. For example, the lower esophageal sphincter (or cardiac sphincter), which resides at the top of the stomach, keeps stomach acids and other stomach contents from pushing up and into the esophagus. During contraction of sphincter/circular muscles, the lumen (opening) associated with the sphincter constricts (closes). This constriction is caused by the shortening of the sphincter muscle. Relaxation of a sphincter muscle causes it to lengthen, opening the lumen.

Classifications

Sphincters can be further classified into functional and anatomical sphincters:

• Anatomical sphincters have a localised and often circular muscle thickening to facilitate their action as a sphincter.
• Functional sphincters do not have this localised muscle thickening and achieve their sphincteric action through muscle contraction around (extrinsic) or within (intrinsic) the structure.

Sphincters can also be voluntarily or involuntarily controlled:

• Voluntary sphincters are supplied by somatic nerves.
• Involuntary sphincters are stimulated by autonomic nerves.

Examples

Diagram of Ileocaecal valve and sphincter

• The sphincter pupillae, or pupillary sphincter, belonging to the iris in the eye.
• The orbicularis oculi muscle, a muscle around the eye.
• The upper and lower oesophageal sphincters.
• The lower sphincter, or cardiac sphincter, at the upper portion (cardia) of the stomach. This sphincter prevents the acidic contents of the stomach from moving upward into the esophagus.
• The pyloric sphincter, at the lower end of the stomach.
• The ileocecal sphincter at the junction of the small intestine (ileum) and the large intestine, which functions to limit the reflux of colonic contents back into the ileum.
• The sphincter of Oddi, or Glisson's sphincter, controlling secretions from the liver, pancreas and gall bladder into the duodenum.
• The sphincter urethrae, or urethral sphincter, controlling the exit of urine from the body.
• At the anus, there are two sphincters which control the exit of feces from the body (see internal anal sphincter and external anal sphincter). The inner sphincter is involuntary and the outer is voluntary.
• The microscopic precapillary sphincters function to control the blood flow into each capillary in response to local metabolic activity.
• The preputial sphincter, belonging to the human foreskin.

UpToDate Contents

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• 1. 妊娠および経膣分娩が肛門括約筋および便失禁に及ぼす影響 effect of pregnancy and childbirth on anal sphincter function and fecal incontinence
• 2. オッディ括約筋機能不全の臨床症状よび診断 clinical manifestations and diagnosis of sphincter of oddi dysfunction
• 3. 肛門括約筋断裂の待機手術によるマネージメント delayed surgical management of the disrupted anal sphincter
• 4. オッディ括約筋機能不全の治療 treatment of sphincter of oddi dysfunction
• 5. 成人における便失禁：疫学および評価 fecal incontinence in adults etiology and evaluation

English Journal

• Confocal microscopy reveals uniform male reproductive anatomy in eriophyoid mites (Acariformes, Eriophyoidea) including spermatophore pump and paired vasa deferentia.

• Chetverikov PE1.
• Experimental & applied acarology.Exp Appl Acarol.2015 Jun 5. [Epub ahead of print]
• Male internal genitalia of eriophyoid mites comprise cuticle lined (anterior genital apodeme, genital chamber and ductus ejculatorius) and soft (paired vasa deferentia and single testis) organs. Three-dimensional reconstructions based on autofluorescence show that a thin-walled genital chamber is us
• PMID 26043829

• Circular and Longitudinal Muscles Shortening Indicates Sliding Patterns during Peristalsis & Transient Lower Esophageal Sphincter Relaxation.

• Patel N1, Jiang Y2, Mittal RK2, Kim TH3, Ledgerwood M2, Bhargava V4.
• American journal of physiology. Gastrointestinal and liver physiology.Am J Physiol Gastrointest Liver Physiol.2015 Jun 4:ajpgi.00067.2015. doi: 10.1152/ajpgi.00067.2015. [Epub ahead of print]
• BACKGROUND: Esophageal axial shortening is caused by longitudinal muscle (LM) contraction but circular muscle (CM) may also contribute to axial shortening because of its spiral morphology. Goal of our study was to show patterns of contraction of CM and LM layers during peristalsis and transient LES
• PMID 26045610

• [Motility disorders of the colon].

• Müller-Lissner S1.
• Der Internist.Internist (Berl).2015 Jun;56(6):648-52. doi: 10.1007/s00108-014-3607-6.
• The motility of the colon is modulated by the enteric nervous system. It is very complex, governing backward and forward movements of the feces. Primary megacolon and megarectum are clinically diverse. Megacolon refractory to laxative treatment may be subject to colectomy, while megarectum should be
• PMID 25940144

Japanese Journal

• A study of profound anal fistula using transrectal ultrasonography.

• 鈴木 紳一郎
• 日本大腸肛門病学会雑誌 43(7), 1301-1310, 1990
• … All confirmed lesions were classified into the following groups based on Sumikoshi's Classification : 1) proximal lesions between the internal/external anal sphincter (II L S), 2) distal lesions between the internal/external anal sphincter (II H S, II H C), 3) lesions at the ischiorectal fossa (IIIU, III B, ITIPr), and 4) lesions above the musculus levator ani (I H--above the levator muscle, IT H-- above the levator muscle, IV-- in the superficial area, IV-- in the deep area). …
• NAID 130000783356

• <原著>末梢自律神経の終末装置の組織学的構造 1.モルモット瞳孔括約筋

• 笹本 真理子
• 山梨医科大学雑誌 5(1), 41-50, 1990
• NAID 110000499881

• 406 Reconstruction of Anal Sphincter with Pedicled Musculus Glutaeus Maximus for Carcinoma of the Lower Third of the Rectum and Anal Canal

• Ping-Zhi Wang,Si-Cong Tang,Ren-Wei Chu
• 日本消化器外科学会雑誌 19(6), 1375, 1986-06-01
• NAID 110001304932

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★リンクテーブル★

リンク元	「括約筋」
拡張検索	「musculus sphincter pupillae」「musculus sphincter ampullae hepatopancreaticae」
関連記事	「sphincter」

「括約筋」

　　[★]

英

sphincter muscle, sphincter

ラ

musculus sphincter

「musculus sphincter pupillae」

　　[★]

瞳孔括約筋

関

pupillary sphincter

「musculus sphincter ampullae hepatopancreaticae」

　　[★] 胆膵管膨大部括約筋

「sphincter」

　　[★]

括約筋

関

sphincter muscle、sphincteral