Editing Sphincter (section)

{{Short description|Circular muscle that normally maintains constriction of a natural body passage or orifice}}
{{Infobox muscle
| Name = Sphincter
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{{Wiktionary}}
A '''sphincter''' is a circular [[muscle]] that normally maintains constriction of a natural body passage or orifice and  relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the [[human body]],{{Citation needed|date=December 2023}} some microscopically small, in particular the millions of [[precapillary sphincter]]s.<ref name="vander-6th">{{cite book|last=Vander|first=Arthur|title=Human Physiology: The Mechanism of Body Function|url=https://archive.org/details/humanphysiology000vand|url-access=limited|year=1994|publisher=McGraw Hill, Inc|isbn=0-07-113761-0|pages=[https://archive.org/details/humanphysiology000vand/page/437 437]–440|author2=Sherman, James |author3= Luciano, Dorothy |edition=Sixth Edition, International }}</ref> Sphincters relax at [[death]], often releasing [[Body fluid|fluids]] and [[faeces]].<ref>{{cite web|url=http://www.medscape.com/viewarticle/716463_5|title=The Last Hours of Living: Practical Advice for Clinicians|website=[[Medscape]]|first1=Linda L.|last1=Emanuel|first2=Frank D.|last2=Ferris|first3=Charles F.|last3=von Gunten|first4=Joshua M.|last4=Hauser|first5=Jamie H.|last5=Von Roenn|date=February 11, 2010}}</ref>