external anal sphincter

外肛門括約筋

WordNet

1. purely outward or superficial; "external composure"; "an external concern for reputation"- A.R.Gurney,Jr.
2. outward features; "he enjoyed the solemn externals of religion"
3. coming from the outside; "extraneous light in the camera spoiled the photograph"; "relying upon an extraneous income"; "disdaining outside pressure groups" (同)extraneous, outside
4. from or between other countries; "external commerce"; "international trade"; "developing nations need outside help" (同)international, outside
5. happening or arising or located outside or beyond some limits or especially surface; "the external auditory canal"; "external pressures"
6. of or related to the anus; "anal thermometer"
7. 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
8. a ring of muscle that contracts to close an opening (同)anatomical sphincter, sphincter_muscle
9. a nonresident doctor or medical student; connected with a hospital but not living there (同)medical extern

PrepTutorEJDIC

1. 『外側の』,外部の / (作用・動作などが)『外側からの』,外部からの / 表面上の,見せかけの / 体外の;体外用の / 外国の(foreign) / (…の)外観,外形《+『of』+『名』》
2. 肛門(こうもん)(anus)の
3. 括約筋(かつやくきん)
4. (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）』「2015/07/23 04:35:16」(JST)

wiki en

[Wiki en表示]

Sphincter ani externus 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. Sphincter ani externus.
Details
Latin	Musculus sphincter ani externus
Nerve	Branch from the fourth sacral and contributions from the inferior hemorrhoidal branch of the pudendal nerve
Actions	Keep the anal canal and orifice closed
Identifiers
Gray's	p.425
Dorlands /Elsevier	m_22/12550801
TA	A04.5.04.012
FMA	21930
Anatomical terms of muscle

The external anal sphincter (or sphincter ani externus ) is a flat plane of muscular fibers, elliptical in shape and intimately adherent to the integument surrounding the margin of the anus.

Anatomy

It measures about 8 to 10 cm in length, from its anterior to its posterior extremity, and is about 2.5 cm opposite the anus, when defecation occurs the sphincter muscle retracts.

It consists of two strata, superficial and deep.

• The superficial, constituting the main portion of the muscle, arises from a narrow tendinous band, the anococcygeal raphe, which stretches from the tip of the coccyx to the posterior margin of the anus; it forms two flattened planes of muscular tissue, which encircle the anus and meet in front to be inserted into the central tendinous point of the perineum, joining with the Transversus perinæi superficialis, the Levator ani, and the Bulbocavernosus.

• The deeper portion forms a complete sphincter to the anal canal. Its fibers surround the canal, closely applied to the internal anal sphincter, and in front blend with the other muscles at the central point of the perineum.

In a considerable proportion of cases the fibers decussate in front of the anus, and are continuous with the Transversi perinæi superficiales.

Posteriorly, they are not attached to the coccyx, but are continuous with those of the opposite side behind the anal canal.

The upper edge of the muscle is ill-defined, since fibers are given off from it to join the Levator ani.

Actions

The action of this muscle is peculiar.

(1) It is, like other muscles, always in a state of tonic contraction, and having no antagonistic muscle it keeps the anal canal and orifice closed.

(2) It can be put into a condition of greater contraction under the influence of the will, so as more firmly to occlude the anal aperture, in expiratory efforts unconnected with defecation.

(3) Taking its fixed point at the coccyx, it helps to fix the central point of the perineum, so that the bulbospongiosus muscle may act from this fixed point.

Pathology

Anismus is a paradoxical contraction of the external anal sphincter, when the intent is relaxation, which can result in obstructed defecation and constipation. Abnormal function of this muscle is also seen in anorectal malformation and after certain surgeries, including coccygectomy.

Additional images

• Intestines

• Schematic demonstrating the anatomy of hemorrhoids.

• Muscles of male perineum.

• Muscles of the female perineum.

• Vertical section of bladder, penis, and urethra.

See also

• Puborectalis muscle

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

External links

• Anatomy photo:42:13-0100 at the SUNY Downstate Medical Center - "The Male Perineum and the Penis: The External Anal Sphincter"
• perineum at The Anatomy Lesson by Wesley Norman (Georgetown University) (analtriangle3)
• 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 fecal incontinence in adults
• 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. 妊娠および経膣分娩に関連した便失禁 fecal incontinence associated with pregnancy and childbirth
• 4. 便失禁の評価における直腸超音波内視鏡検査 endorectal endoscopic ultrasound in the evaluation of fecal incontinence
• 5. 出産に伴う会陰切開および会陰裂傷の修復 repair of episiotomy and perineal lacerations associated with childbirth

English Journal

• Transoesophageal spinal cord stimulation for motor-evoked potentials monitoring: feasibility, safety and stability†.

• Tsuda K1, Shiiya N2, Takahashi D1, Ohkura K1, Yamashita K1, Kando Y1.
• European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery.Eur J Cardiothorac Surg.2015 Aug;48(2):245-51. doi: 10.1093/ejcts/ezu496. Epub 2014 Dec 18.
• OBJECTIVES: Specificity of transcranial motor-evoked potentials (MEPs) is low because amplitude fluctuation is common, which seems due to several technical and fundamental reasons including difficulty in electrodes positioning and fixation for transcranial stimulation and susceptibility to anaesthes
• PMID 25527173

• 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 Aug;26(8):1191-9. doi: 10.1007/s00192-015-2676-y. Epub 2015 Jun 18.
• 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

• Alteration of anal sphincter function in patients with levator avulsion: observational study.

• Guedea MA1, Zambrano JL, Fons JB, Viana LJ, Linaje BO, Milio JÁ.
• International urogynecology journal.Int Urogynecol J.2015 Jul;26(7):985-90. doi: 10.1007/s00192-014-2623-3. Epub 2015 Feb 3.
• INTRODUCTION AND HYPOTHESIS: The prevalence of levator avulsion after vaginal delivery ranges from 10 to 30 %. To our knowledge, no previous studies have used anorectal manometry (AM) to assess this injury's impact on the functionality of the anal sphincter complex. We hypothesized that women with
• PMID 25644050

Japanese Journal

• 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

• 下部直腸・肛門管と腟の接合部の組織構築と神経分布

• 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,阿部 伸一
• 日本大腸肛門病学会雑誌 67(1), 8-15, 2014
• 下部直腸・肛門管と腟の間の組織構築および神経分布を検索するため，成人献体10体から矢状断ないし斜め水平断の組織切片を作成，弾性線維染色および神経免疫組織染色を施した．矢状断では，弾性線維に富む連合縦走筋が，会陰体外側延長部（LEPB）と内肛門括約筋の間を下行，外肛門括約筋に放散していた．前束と後束に分かれ，前束がLEPB内に放散することもあった．いわゆる直腸腟中隔は薄くかつ寸断されており，下部直腸 …
• NAID 130003385086

• 下部直腸癌に対する内括約筋切除肛門温存術(外括約筋切除を含む)の手術成績,遠隔成績,肛門機能について (特集 下部直腸癌に対する機能温存術式 : 第113回日本外科学会定期学術集会パネルディスカッションより)

• 白水 和雄,赤木 由人,衣笠 哲史 [他]
• 癌の臨床 = Japanese journal of cancer clinics 59(6), 665-672, 2013-12
• NAID 40020186391

Related Links

• External anal sphincter | Flickr - Photo Sharing!

+ Add humantestpattern Member since 2008 Taken on January 4, 2004 Fujifilm FinePix S5100 461 Views 0 Galleries

• external anal sphincter (anatomy) -- Encyclopedia Britannica

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★リンクテーブル★

リンク元	「外肛門括約筋」
関連記事	「external」「anal」「sphincter」

「外肛門括約筋」

　　[★]

英

external anal sphincter (M,K), external sphincter muscle of anus

ラ

musculus sphincterani externus

関

肛門括約筋、肛門

• 肛門を楕円形に取り巻く。横紋筋
• 皮下に付着したり、腹側では会陰腱中心に付いたり、背側では腱性(肛門尾骨靭帯)となって尾骨に付いたりする (KH.256)
• 3つの部分に分けられる

• 皮下部
• 浅部
• 深部

「external」

　　[★]

• adj.

• 外部の、外側の、外の

関

exo、exterior、externally、extra、lateral、laterale、lateralis、laterally、outer、outside

　 　 　 　 　 　

「anal」

　　[★]

• adj.

• 肛門の、(analytical等の略)分析

関

analyse、analyses、analysis、analytical、analyze、ani、anus、assay、dissect

　 　 　

「sphincter」

　　[★]

括約筋

関

sphincter muscle、sphincteral