肛門周囲の

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/08/12 22:12:48」(JST)

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The anus (from Latin anus meaning "ring", "circle") is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may include: matter which the animal cannot digest, such as bones;^[1] food material after all the nutrients have been extracted, for example cellulose or lignin; ingested matter which would be toxic if it remained in the digestive tract; and dead or excess gut bacteria and other endosymbionts.

Amphibians, reptiles, and birds use the same orifice (known as the cloaca) for excreting liquid and solid wastes, for copulation and egg-laying. Monotreme mammals also have a cloaca, which is thought to be a feature inherited from the earliest amniotes via the therapsids. Marsupials have a single orifice for excreting both solids and liquids and, in females, a separate vagina for reproduction. Female placental mammals have completely separate orifices for defecation, urination, and reproduction; males have one opening for defecation and another for both urination and reproduction, although the channels flowing to that orifice are almost completely separate.

The development of the anus was an important stage in the evolution of multicellular animals. It appears to have happened at least twice, following different paths in protostomes and deuterostomes. This accompanied or facilitated other important evolutionary developments: the bilaterian body plan, the coelom, and metamerism, in which the body was built of repeated "modules" which could later specialize, such as the heads of most arthropods, which are composed of fused, specialized segments.

Development

In animals at least as complex as an earthworm, the embryo forms a dent on one side, the blastopore, which deepens to become the archenteron, the first phase in the growth of the gut. In deuterostomes, the original dent becomes the anus while the gut eventually tunnels through to make another opening, which forms the mouth. The protostomes were so named because it was thought that in their embryos the dent formed the mouth first (proto– meaning "first") and the anus was formed later at the opening made by the other end of the gut. More recent research, however, shows that in protostomes the edges of the dent close up in the middle, leaving openings at the ends which become the mouth and anus.^[2]

References

^ Chin, K.; Erickson, G.M.; et al. (1998-06-18). "A king-sized theropod coprolite". Nature. 393 (6686): 680. doi:10.1038/31461. Summary at Monastersky, R. (1998-06-20). "Getting the scoop from the poop of T. rex". Science News. Society for Science &#38. 153 (25): 391. JSTOR 4010364. doi:10.2307/4010364.
^ Arendt, D.; Technau, U. & Wittbrodt, J. (4 January 2001). "Evolution of the bilaterian larval foregut". Nature. 409 (6816): 81–85. PMID 11343117. doi:10.1038/35051075. Retrieved 2008-07-14.

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UpToDate Contents

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1. 肛門周囲膿瘍：臨床症状、診断、および治療 perianal abscess clinical manifestations diagnosis treatment
2. クローン病の肛門合併症 perianal complications of crohn disease
3. 肛門直腸瘻：臨床症状、診断、およびマネージメントの原則 anorectal fistula clinical manifestations diagnosis and management principles
4. 肛門そう痒症患者へのアプローチ approach to the patient with anal pruritus
5. 小児および思春期におけるクローン病マネージメントの概要 overview of the management of crohn disease in children and adolescents

English Journal

Systematic review: thalidomide and thalidomide analogues for treatment of inflammatory bowel disease.

Yang C1, Singh P, Singh H, Le ML, El-Matary W.
Alimentary pharmacology & therapeutics.Aliment Pharmacol Ther.2015 Jun;41(11):1079-93. doi: 10.1111/apt.13181. Epub 2015 Apr 8.
BACKGROUND: It has been reported that thalidomide may be effective in treating inflammatory bowel disease (IBD).AIM: To review the evidence examining the efficacy and safety of thalidomide for inducing and maintaining remission in Crohn's disease (CD) and ulcerative colitis (UC).METHODS: The Cochran
PMID 25858208

Extramammary Paget's Disease in Males: Survival Outcomes in 495 Patients.

Herrel LA1, Weiss AD, Goodman M, Johnson TV, Osunkoya AO, Delman KA, Master VA.
Annals of surgical oncology.Ann Surg Oncol.2015 May;22(5):1625-30. doi: 10.1245/s10434-014-4139-y. Epub 2014 Nov 11.
BACKGROUND: Extramammary Paget's disease (EMPD) is a rare intraepithelial malignancy with poorly described outcomes. EMPD in men is primarily found in the perianal and penoscrotal areas. We assessed incidence and time trends of EMPD in men as well as extent and predictors of survival using the Surve
PMID 25384700

Perianal giant condyloma acuminatum of Buschke-Loewenstein: a carcinoma-like condyloma or a condyloma-like carcinoma?

Virgilio E1, Balducci G, Mercantini P, Tozzi F, Ziparo V, Ferri M.
ANZ journal of surgery.ANZ J Surg.2015 May;85(5):394-5. doi: 10.1111/ans.12913.
PMID 25899838

Japanese Journal

肛門周囲の腺腫(腺癌) (特集肛門・肛門周囲の外科)

Surgeon : technical magazine for veterinary surgeons : 小動物外科専門誌 21(3), 45-67, 2017-05
NAID 40021224798

肛門周囲瘻 (特集肛門・肛門周囲の外科)

Surgeon : technical magazine for veterinary surgeons : 小動物外科専門誌 21(3), 36-44, 2017-05
NAID 40021224790

UK VET翻訳肛門囊の疾患および肛門周囲瘻

J-vet : jounral for veterinary practitioner 30(4), 60-67, 2017-04
NAID 40021185767

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拡張検索	「perianal abscess」「perianal Paget disease」

「perianal abscess」

Anus
	Formation of anus in proto- and deuterostomes
Details
Precursor	Proctodeum
System	Alimentary, sometimes reproductive
Artery	Inferior rectal artery
Vein	Inferior rectal vein
Nerve	Inferior rectal nerves
Lymph	Superficial inguinal lymph nodes
Identifiers
Latin	Anus
TA	A05.7.05.013
FMA	15711
	Anatomical terminology [edit on Wikidata]

　　[★] 直腸肛門周囲膿瘍。肛門周囲膿瘍

「perianal Paget disease」

　　[★] 肛門部パジェット病

[ChinEtal1998KingSizeCoprolite-1] Chin, K.; Erickson, G.M.; et al. (1998-06-18). "A king-sized theropod coprolite". Nature. 393 (6686): 680. doi:10.1038/31461. Summary at Monastersky, R. (1998-06-20). "Getting the scoop from the poop of T. rex". Science News. Society for Science &#38. 153 (25): 391. JSTOR 4010364. doi:10.2307/4010364.

[2] Arendt, D.; Technau, U. & Wittbrodt, J. (4 January 2001). "Evolution of the bilaterian larval foregut". Nature. 409 (6816): 81–85. PMID 11343117. doi:10.1038/35051075. Retrieved 2008-07-14.

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