WordNet

work as an intern; "The young doctor is interning at the Medical Center this year"
an advanced student or graduate in medicine gaining supervised practical experience (`houseman is a British term) (同)interne, houseman, medical intern
deprive of freedom; "During WW II, Japanese were interned in camps in the West"
happening or arising or located within some limits or especially surface; "internal organs"; "internal mechanism of a toy"; "internal party maneuvering"
occurring within an institution or community; "intragroup squabbling within the corporation" (同)intragroup
of or related to the anus; "anal thermometer"
a stage in psychosexual development when the childs interest is concentrated on the anal region; fixation at this stage is said to result in orderliness, meanness, stubbornness, compulsiveness, etc. (同)anal retentive
a ring of muscle that contracts to close an opening (同)anatomical sphincter, sphincter_muscle

PrepTutorEJDIC

(特に戦時中)〈人・船など〉‘を'強制収容する,抑留する
『内側の』,内部にある / 『国内の』(domestic) / 内からとる,内用の
肛門(こうもん)(anus)の
括約筋(かつやくきん)
(次にくる語の発音が母音で始まるときに用いる) / (子音[h]で始まり第1音節に強勢のない語の場合はanを用いることがある.ただし,この場合は[h]を発音しない)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/07/22 18:59:49」(JST)

wiki en

The sphincter ani internus (or internal anal sphincter, IAS) is a muscular ring that surrounds about 2.5-4.0 cm of the anal canal; its inferior border is in contact with, but quite separate from, the sphincter ani externus.

It is about 5 mm thick, and is formed by an aggregation of the involuntary circular fibers of the rectum. Its lower border is about 6 mm from the orifice of the anus.

Actions

Its action is entirely involuntary, and it is in a state of continuous maximal contraction. It helps the Sphincter ani externus to occlude the anal aperture and aids in the expulsion of the feces. Sympathetic fibers from the superior rectal and hypogastric plexuses stimulate and maintain internal anal sphincter contraction. Its contraction is inhibited by parasympathetic fiber stimulation. This sphincter is tonically contracted most of the time to prevent leakage of fluid or gas, but is relaxed upon distention of the rectal ampulla, requiring voluntary contraction of the puborectalis and external anal sphincter.^[1] The internal anal sphincter is not innervated by the pudendal nerve, which carries somatic (motor and sensory) fibers that provide the innervation to the external anal sphincter.^[2]

Role in continence

The IAS contributes 55% of the resting pressure of the anal canal. It is very important for bowel continence, especially for liquid and gas. When the rectum fills beyond a certain capacity, the rectal walls are distended, triggering the defecation cycle. This begins with the rectoanal inhibitory reflex, RAIR, where the IAS relaxes. This is thought to allow a small amount of rectal contents to descend into the anal canal where specialized mucosa samples whether it is gas, liquid or solid. Problems with the IAS often present as degrees of fecal incontinence (especially partial incontinence to liquid) or mucous rectal discharge.^[3]

Additional images

Intestines
Schematic demonstrating the anatomy of hemorrhoids.

References

^ Moore, K., Dalley, A., Ague, A. "Clinically Oriented Anatomy. 6th Edition.
^ http://www.dartmouth.edu/~humananatomy/part_6/chapter_36.html
^ al.], senior editors, Bruce G. Wolff ... [et (2007). The ASCRS textbook of colon and rectal surgery. New York: Springer. ISBN 0-387-24846-3.

This article incorporates text from a public domain edition of Gray's Anatomy.

External links

Origin, insertion and nerve supply of the muscle at Loyola University Chicago Stritch School of Medicine
pelvis at The Anatomy Lesson by Wesley Norman (Georgetown University) (rectum)

UpToDate Contents

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1. 成人における便失禁：疫学および評価 fecal incontinence in adults etiology and evaluation
2. 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
3. 成人における便失禁：マネージメント fecal incontinence in adults management
4. 成人における慢性便秘の病因および評価 etiology and evaluation of chronic constipation in adults
5. 切除可能原発性直腸癌の手術の概要 overview of surgical procedures for resectable primary rectal cancer

English Journal

The relationship of 3-D translabial ultrasound anal sphincter complex measurements to postpartum anal and fecal incontinence.

Meriwether KV1, Hall RJ, Leeman LM, Migliaccio L, Qualls C, Rogers RG.
International urogynecology journal.Int Urogynecol J.2015 Jun 18. [Epub ahead of print]
INTRODUCTION AND HYPOTHESIS: We aimed to determine whether anal sphincter complex (ASC) measurements on translabial ultrasound (TL-US) were related to anal incontinence (AI) or fecal incontinence (FI) symptoms 6 months postpartum.METHODS: A prospective cohort of primiparous women underwent TL-US 6�
PMID 26085463

Use of hollow microneedles for targeted delivery of phenylephrine to treat fecal incontinence.

Jun H1, Han MR2, Kang NG3, Park JH4, Park JH5.
Journal of controlled release : official journal of the Controlled Release Society.J Control Release.2015 Jun 10;207:1-6. doi: 10.1016/j.jconrel.2015.03.031. Epub 2015 Mar 28.
A hollow microneedle (HM) was prepared to deliver a phenylephrine (PE) solution into the anal sphincter muscle as a method for treating fecal incontinence. The goal of this study was the local targeted delivery of PE into the sphincter muscle through the perianal skin with minimal pain using hollow
PMID 25828366

Endoanal ultrasonography in fecal incontinence: Current and future perspectives.

Albuquerque A1.
World journal of gastrointestinal endoscopy.World J Gastrointest Endosc.2015 Jun 10;7(6):575-81. doi: 10.4253/wjge.v7.i6.575.
Fecal incontinence has a profound impact in a patient's life, impairing quality of life and carrying a substantial economic burden due to health costs. It is an underdiagnosed condition because many affected patients are reluctant to report it and also clinicians are usually not alert to it. Patient
PMID 26078826

Japanese Journal

直腸脱に対する会陰式肛門管形成手術 : 内肛門括約筋後方形成手術 (特集骨盤臓器脱診断・治療のすべて) -- (治療)

大見良裕,大見琢磨,大見究磨
外科 = Surgey : 臨床雑誌 76(6), 601-606, 2014-06
NAID 40020106411

傍腟組織と直腸・肛門管の神経連絡

秦史壮,荒川高志,岡田邦明,西森英史,池田慎一郎,山田真美,平間知美,矢嶋知己,石山元太郎,阿部伸一
日本大腸肛門病学会雑誌 67(8), 495-503, 2014
傍腟組織と直腸・肛門管は，直腸間膜によって遠く隔てられた構造と思われがちだが，両者の間には神経連絡があると推測される．成人女性献体10体から前頭断類似の組織切片を作成，平滑筋および神経の免疫組織染色を施した．傍腟組織は多数の神経および神経節を含み，恥頸筋膜とデノビエ筋膜がそれぞれ前後の境界を，上骨盤隔膜筋膜が外側縁をなしていた．肛門挙筋が腟に近接する高さでは，傍腟組織の前後をはさむ筋膜が不明瞭にな …
NAID 130004679123

肛門括約筋機能不全における肛門管超音波検査での再現性と有用性

田島雄介,田中荘一,相川佳子,長嶋康雄,松田聡,尾田典隆,野中雅彦,木村浩三,中井勝彦,川上和彦,松田保秀
日本大腸肛門病学会雑誌 67(4), 253-258, 2014
肛門管超音波検査は低侵襲，簡便という利点を有するが，所見の再現性が議論されることもある．肛門管超音波検査による肛門括約筋所見の再現性と有用性を明らかにする目的で，肛門管超音波所見をレトロスペクティブに再評価し，所見の有無で肛門内圧に差がないか検討した．対象は肛門管超音波と肛門内圧検査を施行された女性患者33例．4人の技師が超音波画像を再評価し，肛門括約筋の同定，途絶有無，厚不整有無を再現性という観 …
NAID 130003394587

「内肛門括約筋」

Sphincter ani internus muscle
	Coronal section through the anal canal. B. Cavity of urinary bladder V.D. Ductus deferens. S.V. Seminal vesicle. R. Second part of rectum. A.C. Anal canal. L.A. Levator ani. I.S. Sphincter ani internus. E.S. Sphinear ani externus.
	Coronal section of rectum and anal canal.
Latin	Musculus sphincter ani internus
Gray's	p.426
Nerve	Pelvic splanchnic nerves (S4), thoracicolumbar outflow of the spinal cord
Actions	Keep the anal canal and orifice closed, aids in the expulsion of the feces
	Anatomical terms of muscle