Editing Vagina (section)

===Gross anatomy===
{{See also|Vaginal support structures}}
[[File:Blausen 0400 FemaleReproSystem 02b.png|thumb|upright=1.36|alt=Diagram illustrating female pelvic anatomy|Pelvic anatomy including organs of the female reproductive system]]

The human vagina is an elastic, muscular canal that extends from the vulva to the cervix.<ref name="Snell">{{cite book|vauthors=Snell RS|title=Clinical Anatomy: An Illustrated Review with Questions and Explanations|url=https://books.google.com/books?id=5s7jDVQkCfoC&pg=PA98|year=2004|publisher=Lippincott Williams & Wilkins|isbn=978-0-7817-4316-7|page=98|access-date=October 27, 2015|archive-date=March 10, 2021|archive-url=https://web.archive.org/web/20210310000538/https://books.google.com/books?id=5s7jDVQkCfoC&pg=PA98|url-status=live}}</ref><ref name="Dutta">{{cite book|vauthors=Dutta DC|title=DC Dutta's Textbook of Gynecology|year=2014|publisher=JP Medical Ltd|isbn=978-93-5152-068-9|pages=2–7|url=https://books.google.com/books?id=40yVAwAAQBAJ&pg=PA2|access-date=October 27, 2015|archive-date=July 4, 2019|archive-url=https://web.archive.org/web/20190704043225/https://books.google.com/books?id=40yVAwAAQBAJ&pg=PA2|url-status=live}}</ref> The opening of the vagina lies in the [[urogenital triangle]]. The urogenital triangle is the front triangle of the [[perineum]] and also consists of the urethral opening and associated parts of the external genitalia.<ref name="Drake">{{cite book|vauthors=Drake R, Vogl AW, Mitchell A|title=Gray's Basic Anatomy E-Book|year=2016|publisher=[[Elsevier Health Sciences]]|isbn=978-0-323-50850-6|page=246|url=https://books.google.com/books?id=fojKDQAAQBAJ&pg=PA246|access-date=May 25, 2018|archive-date=June 4, 2021|archive-url=https://web.archive.org/web/20210604234718/https://books.google.com/books?id=fojKDQAAQBAJ&pg=PA246|url-status=live}}</ref> The '''vaginal canal''' travels upwards and backwards, between the urethra at the front, and the rectum at the back. Near the upper vagina, the cervix protrudes into the vagina on its front surface at approximately a 90 degree angle.<ref name="Mulhall">{{cite book |vauthors=Ginger VA, Yang CC |chapter=Functional Anatomy of the Female Sex Organs |veditors=Mulhall JP, Incrocci L, Goldstein I, Rosen R |title=Cancer and Sexual Health |isbn=978-1-60761-915-4 |publisher=[[Springer Publishing|Springer]] |year=2011 |pages=13, 20–21 |chapter-url=https://books.google.com/books?id=GpIadil3YsQC&pg=PA13 |access-date=August 20, 2020 |archive-date=December 16, 2019 |archive-url=https://web.archive.org/web/20191216021705/https://books.google.com/books?id=GpIadil3YsQC&pg=PA13 |url-status=live }}</ref> The vaginal and urethral openings are protected by the labia.<ref name="Kinetics2009">{{cite book|vauthors=Ransons A|chapter=Reproductive Choices|title=Health and Wellness for Life|chapter-url=https://books.google.com/books?id=2GZ7N4wOeGYC&pg=PA221|date=May 15, 2009|publisher=Human Kinetics 10%|isbn=978-0-7360-6850-5|page=221|access-date=October 27, 2015|archive-date=May 6, 2016|archive-url=https://web.archive.org/web/20160506004528/https://books.google.com/books?id=2GZ7N4wOeGYC&pg=PA221|url-status=live}}</ref>

When not [[sexually aroused]], the vagina is a collapsed tube, with the front and back walls placed together. The lateral walls, especially their middle area, are relatively more rigid. Because of this, the collapsed vagina has an H-shaped cross section.<ref name="Dutta"/><ref name="Beckmann 2">{{cite book|vauthors=Beckmann CR|title=Obstetrics and Gynecology|publisher=[[Lippincott Williams & Wilkins]]|isbn=978-0-7817-8807-6|page=37|year=2010|url=https://books.google.com/books?id=0flWgd3OJLEC&pg=PA37|quote=Because the vagina is collapsed, it appears H-shaped in cross section.|access-date=January 31, 2017|archive-date=February 15, 2017|archive-url=https://web.archive.org/web/20170215191755/https://books.google.com/books?id=0flWgd3OJLEC&pg=PA37|url-status=live}}</ref> Behind, the upper vagina is separated from the [[rectum]] by the [[recto-uterine pouch]], the middle vagina by loose [[connective tissue]], and the lower vagina by the [[Perineum#Body|perineal body]].<ref name=GRAYS2008>{{cite book |veditors=Standring S, Borley NR |title=Gray's anatomy : the anatomical basis of clinical practice|date=2008|publisher=Churchill Livingstone|location=London|isbn=978-0-8089-2371-8|edition=40th|pages=1281–4}}</ref> Where the vaginal [[Lumen (anatomy)|lumen]] surrounds the cervix of the uterus, it is divided into four continuous regions ([[vaginal fornices]]); these are the anterior, posterior, right lateral, and left lateral fornices.<ref name="Snell"/><ref name="Dutta"/> The posterior fornix is deeper than the anterior fornix.<ref name="Dutta"/>

Supporting the vagina are its upper, middle, and lower third muscles and ligaments. The upper third are the [[levator ani]] muscles, and the transcervical, [[Pubocervical ligament|pubocervical]], and sacrocervical ligaments.<ref name="Snell"/><ref name="Baggish">{{cite book|vauthors=Baggish MS, Karram MM|title=Atlas of Pelvic Anatomy and Gynecologic Surgery - E-Book|year=2011|page=582|publisher=[[Elsevier Health Sciences]]|isbn=978-1-4557-1068-3|url=https://books.google.com/books?id=lwWldKFVPYYC&pg=PA582|access-date=May 7, 2018|archive-date=July 4, 2019|archive-url=https://web.archive.org/web/20190704043154/https://books.google.com/books?id=lwWldKFVPYYC&pg=PA582|url-status=live}}</ref> It is supported by the upper portions of the [[cardinal ligament]]s and the [[parametrium]].<ref name="Arulkumaran 1">{{cite book|vauthors=Arulkumaran S, Regan L, Papageorghiou A, Monga A, Farquharson D|title=Oxford Desk Reference: Obstetrics and Gynaecology|year=2011|page=472|publisher=[[OUP Oxford]]|isbn=978-0-19-162087-4|url=https://books.google.com/books?id=lRaWcRYx_7YC&pg=PA472|access-date=May 7, 2018|archive-date=July 3, 2019|archive-url=https://web.archive.org/web/20190703220025/https://books.google.com/books?id=lRaWcRYx_7YC&pg=PA472|url-status=live}}</ref> The middle third of the vagina involves the [[urogenital diaphragm]].<ref name="Snell"/> It is supported by the levator ani muscles and the lower portion of the cardinal ligaments.<ref name="Arulkumaran 1"/> The lower third is supported by the perineal body,<ref name="Snell"/><ref name="Elsevier Obstetrics">{{Cite book |title=Manual of Obstetrics |edition =3rd |publisher=[[Elsevier]] |year=2011 |pages=1–16 |isbn=978-81-312-2556-1}}</ref> or the urogenital and [[pelvic diaphragm]]s.<ref name="Smith 2">{{cite book|vauthors=Smith RP, Turek P|title=Netter Collection of Medical Illustrations: Reproductive System E-Book|year=2011|page=443|publisher=[[Elsevier Health Sciences]]|isbn=978-1-4377-3648-9|url=https://books.google.com/books?id=ySriOOirL_UC&pg=PT443|access-date=May 7, 2018|archive-date=July 3, 2019|archive-url=https://web.archive.org/web/20190703211240/https://books.google.com/books?id=ySriOOirL_UC&pg=PT443|url-status=live}}</ref> The lower third may also be described as being supported by the perineal body and the pubovaginal part of the levator ani muscle.<ref name="Baggish"/>

====Vaginal opening and hymen====
[[File:Vaginal opening description-en.svg|A human vulva with vaginal opening labeled|thumb]]
The '''vaginal opening''' (also known as the '''vaginal introitus''' and the Latin '''''ostium vaginae''''')<ref>{{cite book|last1=Ricci|first1=Susan Scott|last2=Kyle|first2=Terri|publisher=Wolters Kluwer Health/Lippincott Williams & Wilkins|year = 2009|title=Maternity and Pediatric Nursing|page=77|access-date=January 7, 2024|isbn=978-0-78178-055-1|url=https://books.google.com/books?id=gaYtFuND7VIC&pg=PA77}}</ref><ref>{{cite book|last=Zink|first=Christopher|publisher=De Gruyter|year = 2011|title= Dictionary of Obstetrics and Gynecology |page=174|isbn= 978-3-11085-727-6 |url= https://books.google.com/books?id=EQlvzV9V7xIC&pg=PA174}}</ref> is at the posterior end of the [[vulval vestibule]], behind the [[urinary meatus|urethral opening]]. The term ''introitus'' is more technically correct than "opening", since the vagina is usually collapsed, with the opening closed. The opening to the vagina is normally obscured by the [[labia minora]] (inner lips), but may be exposed after [[vaginal delivery]].<ref name="Dutta"/>

The [[hymen]] is a thin layer of [[mucous membrane|mucosal tissue]] that surrounds or partially covers the vaginal opening.<ref name="Dutta"/> The effects of [[sexual intercourse|intercourse]] and childbirth on the hymen vary. Where it is broken, it may completely disappear or remnants known as ''carunculae myrtiformes'' may persist. Otherwise, being very elastic, it may return to its normal position.<ref name="Knight">{{cite book|vauthors=Knight B |title=Simpson's Forensic Medicine|edition=11th|year=1997|publisher=Arnold|location=London|page=114|isbn=978-0-7131-4452-9}}</ref> Additionally, the hymen may be lacerated by disease, injury, [[medical examination]], [[masturbation]] or [[physical exercise]]. For these reasons, [[virginity]] cannot be definitively determined by examining the hymen.<ref name="Knight"/><ref name="Perlman">{{Cite book|vauthors=Perlman SE, Nakajyma ST, Hertweck SP |title=Clinical protocols in pediatric and adolescent gynecology|year=2004|publisher=Parthenon |page=131 |isbn=978-1-84214-199-1 }}</ref>

====Variations and size====
{{Main|Human vaginal size}}
The length of the vagina [[anatomical variation|varies]] among women of child-bearing age. Because of the presence of the cervix in the front wall of the vagina, there is a difference in length between the front wall, approximately 7.5&nbsp;cm (2.5 to 3 in) long, and the back wall, approximately 9&nbsp;cm (3.5&nbsp;in) long.<ref name="Dutta"/><ref name="Wylie"/>  During sexual arousal, the vagina expands both in length and width. If a woman stands upright, the vaginal canal points in an upward-backward direction and forms an angle of approximately 45 degrees with the uterus.<ref name="Dutta"/><ref name="Elsevier Obstetrics"/> The vaginal opening and hymen also vary in size; in children, although the hymen commonly appears [[crescent]]-shaped, many shapes are possible.<ref name="Dutta"/><ref name="Emans">{{cite book|vauthors=Emans SJ|chapter=Physical Examination of the Child and Adolescent|title=Evaluation of the Sexually Abused Child: A Medical Textbook and Photographic Atlas|edition=2nd|publisher=[[Oxford University Press]]|pages=61–65|isbn=978-0-19-974782-5|date=2000|chapter-url=https://books.google.com/books?id=3eQZhs4PwrYC|access-date=August 2, 2015|archive-date=July 4, 2019|archive-url=https://web.archive.org/web/20190704044740/https://books.google.com/books?id=3eQZhs4PwrYC|url-status=live}}</ref>