関: sphincter muscle、sphincteral

WordNet

a ring of muscle that contracts to close an opening (同)anatomical sphincter, sphincter_muscle

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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）』「2014/07/22 23:48:47」(JST)

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Look up sphincter in Wiktionary, the free dictionary.

A sphincter is an anatomical structure, 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 50 types in the human body, some microscopically small, in particular the millions of precapillary sphincters.^[1] Sphincters relax at death, possibly releasing fluids.^[2]

Functions

Sphincters prove effective in the mediation of the entrance or release 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 and vision. For example, the lower esophageal sphincter, which resides at the top of the stomach, keep stomach acids and other stomach contents from pushing up and into the esophagus.

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 cardia (lower esophageal sphincter), or cardiac sphincter, at the upper portion 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.^[1]

References

^ ^a ^b Vander, Arthur; Sherman, James; & Luciano, Dorothy (1994). Human Physiology: The Mechanism of Body Function (Sixth Edition, International Edition). McGraw Hill, Inc. pp. 437–440. ISBN 0-07-113761-0. Cite uses deprecated parameters (help)
^ http://www.medscape.com/viewarticle/716463_5

UpToDate Contents

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1. 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
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. オッディ括約筋機能不全の治療 treatment of sphincter of oddi dysfunction
4. Techniques and devices for airway management for anesthesia: Supraglottic devices (including laryngeal mask airways)
5. Congenital central hypoventilation syndrome and other causes of sleep-related hypoventilation in children

English Journal

Fecal incontinence: the role of the urologist.

Unger CA, Goldman HB, Jelovsek JE.Author information Obstetrics, Gynecology, and Women's Health Institute, Center for Female Pelvic Medicine and Reconstructive Surgery, Cleveland Clinic, Cleveland, OH, 44195, USA, ungerc@ccf.org.AbstractFecal incontinence is the involuntary loss of solid or liquid stool. While the true prevalence of fecal incontinence is difficult to discern, it is estimated that almost 9 % of non-institutionalized women in the US experience this condition. Disorders leading to fecal urgency alone are usually related to rectal storage abnormalities while incontinence is often a result of anatomic or neurologic disruption of the anal sphincter complex. Many risk factors exist for fecal incontinence and include female sex, increasing age, higher body mass index (BMI), limited physical activity, smoking, presence of neuropsychiatric conditions, higher vaginal parity and history of obstetrical trauma, presence of chronic diarrhea and irritable bowel syndrome, or history of rectal surgery, prostatectomy and radiation. Evaluation of fecal incontinence involves a careful patient history and focused physical exam. Diagnostic tests include endorectal ultrasonography, anal manometry, anal sphincter electromyography, and defecography. Treatment strategies include behavioral, medical and surgical therapies as well as neuromodulation. Treatment is based on the presumed etiology of the condition and a multi-modal approach is often necessary to achieve the maximum benefit for patients.
Current urology reports.Curr Urol Rep.2014 Mar;15(3):388. doi: 10.1007/s11934-013-0388-8.
Fecal incontinence is the involuntary loss of solid or liquid stool. While the true prevalence of fecal incontinence is difficult to discern, it is estimated that almost 9 % of non-institutionalized women in the US experience this condition. Disorders leading to fecal urgency alone are usually rela
PMID 24482107

Feedback control of TET system with variable coupling coefficients for a novel artificial anal sphincter.

Ke L, Yan G, Yan S, Wang Z, Liu Z.Author information 820 Institute, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University , Shanghai , PR China.AbstractAbstract For treating severe faecal incontinence, the authors developed an intelligent artificial anal sphincter system (AASS) equipped with a feedback sensor that utilized a transcutaneous energy transfer system (TETS). To deliver the correct amount of power (i.e. to match the load demand under variable coupling conditions caused by changes in positioning between the coils due to fitting and changes in posture), a regulating method to stabilize output voltage with a closed loop variable-frequency controller was developed in this paper. The method via which the voltage gain characteristics of a voltage-fed series-tuned TETS were derived is also described. The theoretical analysis was verified by the results of the experiment. A numerical analysis method was used as a control rule with respect to the relationship between operating frequency and output voltage. To validate the feedback control rules, a prototype of the TET charging system was constructed, and its performance was validated with the coupling variation between 0.12-0.42. The results show that the output voltage of the secondary side can be maintained at a constant 7 V across the whole coupling coefficient range, with a switching frequency regulation range of 271.4-320.5 kHz, and the proposed controller has reached a maximal end-to-end power efficiency of 67.5% at 1 W.
Journal of medical engineering & technology.J Med Eng Technol.2014 Mar;38(2):90-9. doi: 10.3109/03091902.2013.872204. Epub 2014 Jan 8.
Abstract For treating severe faecal incontinence, the authors developed an intelligent artificial anal sphincter system (AASS) equipped with a feedback sensor that utilized a transcutaneous energy transfer system (TETS). To deliver the correct amount of power (i.e. to match the load demand under var
PMID 24400997

MRI of anal cancer: assessing response to definitive chemoradiotherapy.

Gourtsoyianni S, Goh V.Author information Department of Radiology, Guy's & St Thomas' NHS Foundation Trust, Imaging 2, Level 1, Lambeth Wing, St Thomas' Hospital, Lambeth Palace Road, London, SE1 7EH, UK, sgty76@gmail.com.AbstractAnal cancer is an uncommon malignancy of the gastrointestinal tract but has a relatively good prognosis with an 80% 5-year overall survival. In this article, we review the role of MRI for assessing treatment response in anal cancer after completion of definitive chemoradiotherapy. New generation MRI scanners with optimal-phased array body coils, resulting in better signal to noise and improved contrast and spatial resolution, have contributed to high-resolution imaging in clinical practice enabling visualization of relevant anatomy including the sphincter complex, adjacent structures, mesorectal and pelvic lymph nodes with a diameter down to 2 mm. Multiplanar, high-resolution T2-weighted and diffusion-weighted sequences have a role in initial locoregional staging of anal SCC, assisting radiotherapy planning, as well as in assessing response to treatment and treatment-related complications.
Abdominal imaging.Abdom Imaging.2014 Feb;39(1):2-17. doi: 10.1007/s00261-013-0032-6.
Anal cancer is an uncommon malignancy of the gastrointestinal tract but has a relatively good prognosis with an 80% 5-year overall survival. In this article, we review the role of MRI for assessing treatment response in anal cancer after completion of definitive chemoradiotherapy. New generation MRI
PMID 24072381

Japanese Journal

5. 人工括約筋 : 自らがコントロールする生活リズムを取り戻す(<小特集>身体補助具の今-クオリティオブライフの維持に向けて-)

山家智之,白石泰之,三浦英和
電子情報通信学会誌 98(4), 290-294, 2015-04-01
救命だけでなく,QOLも視野においた人工臓器が求められる時代になってきている.完全埋込形の人工括約筋システムでは,患者が自分自身で排便をコントロールできるので,自分の生活リズムを取り戻すことができる.
NAID 110009923181

人工括約筋 : 自らがコントロールする生活リズムを取り戻す (小特集身体補助具の今 : クオリティオブライフの維持に向けて)

山家智之,白石泰之,三浦英和
電子情報通信学会誌 = The journal of the Institute of Electronics, Information and Communication Engineers 98(4), 290-294, 2015-04
NAID 40020423940

症例報告排尿筋外括約筋協調不全を呈したウェルニッケ脳症の1例

谷口昌光,谷口央,長浦主税
Brain and nerve : 神経研究の進歩 67(3), 317-321, 2015-03
NAID 40020386254

ISRの限界例に対し機能と根治性からみたESRの位置づけ (特集括約筋間直腸切除術(ISR)のすべて)

赤木由人,弓削浩太郎,衣笠哲史 [他]
外科 = Surgey : 臨床雑誌 77(3), 297-301, 2015-03
NAID 40020370519

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