Editing Human sexuality (section)

====Female anatomy and reproductive system====
{{Main|Human female reproductive system}}

=====External female anatomy=====

The mons veneris, also known as the [[Mons pubis|Mound of Venus]], is a soft layer of fatty tissue overlaying the pubic bone.<ref>{{cite book|last1=Hyde |last2=DeLamater |last3=Byers|title=Understanding Human Sexuality 5th Canadian ed.|year=2012 |isbn=978-0-07-032972-0|page=78}}</ref> Following puberty, this area grows in size. It has many nerve endings and is sensitive to stimulation.<ref name="ReferenceA"/>{{page needed|date=February 2016}}

The labia minora and labia majora are collectively known as the lips. The labia majora are two elongated folds of skin extending from the mons to the perineum. Its outer surface becomes covered with hair after puberty. In between the labia majora are the labia minora, two hairless folds of skin that meet above the clitoris to form the clitoral hood, which is highly sensitive to touch. The labia minora become engorged with blood during sexual stimulation, causing them to swell and turn red.<ref name="ReferenceA"/>{{page needed|date=February 2016}}

The labia minora are composed of connective tissues that are richly supplied with blood vessels which cause a pinkish appearance. Near the anus, the labia minora merge with the labia majora.<ref name="innerbody.com">{{cite web|url=http://www.innerbody.com/image/repfov.html |title=Female Reproductive System – Anatomy Pictures and Information |publisher=Innerbody.com |access-date=30 June 2013}}</ref> In a sexually unstimulated state, the labia minora protects the vaginal and urethral opening by covering them.<ref>''Human Reproductive Biology'' by Mark M. Jones (2012), p. 63.</ref> At the base of the labia minora are the [[Bartholin's glands]], which add a few drops of an alkaline fluid to the vagina via ducts; this fluid helps to counteract the acidity of the outer vagina since sperm cannot live in an acidic environment.<ref name="ReferenceA"/>{{page needed|date=February 2016}}

The clitoris is developed from the same embryonic tissue as the penis; it or its [[Clitoral glans|glans]] alone consists of as many (or more in some cases) nerve endings as the human penis or glans penis, making it extremely sensitive to touch.<ref name="Francoeur">{{cite book |last=Francoeur |first=Robert T. |year=2000 |title=The Complete Dictionary of Sexology |publisher=The Continuum Publishing Company |page=[https://archive.org/details/completedictiona0000unse_w1u0/page/180 180] |isbn=978-0-8264-0672-9 |url=https://archive.org/details/completedictiona0000unse_w1u0/page/180 }}</ref><ref name="Carroll">{{cite book | title =Sexuality Now: Embracing Diversity | publisher = [[Cengage Learning]] | year = 2009 | page = 118 | access-date =23 June 2012 | url = {{Google books |plainurl=yes |id=5f8mQx7ULs4C |}} |isbn =978-0-495-60274-3 | first = Janell L. | last = Carroll}}</ref><ref name="Can't feel">{{cite web | title = I'm a woman who cannot feel pleasurable sensations during intercourse | publisher = [[Go Ask Alice!]] | date = 8 October 2004| access-date = 13 September 2012|url=http://goaskalice.columbia.edu/im-woman-who-cannot-feel-pleasurable-sensations-during-intercourse |archive-date= 7 January 2011|archive-url = https://web.archive.org/web/20110107184029/http://www.goaskalice.columbia.edu/3229.html}}</ref> The clitoral glans, which is a small, elongated erectile structure, has only one known function—sexual sensations. It is the female's most sensitive [[erogenous zone]] and the [[Portal:Main|main]] source of orgasm in women.<ref name="Clitoris">{{cite web|title=I Want a Better Orgasm!|website=[[WebMD]]|access-date=18 August 2011|url=http://www.webmd.com/sex/want-better-orgasms|archive-url=https://web.archive.org/web/20090113132443/http://www.webmd.com/sex/want-better-orgasms|archive-date=13 January 2009}}</ref><ref name="Flaherty">{{cite book|first1=Joseph A.|last1=Flaherty|first2=John Marcell|last2=Davis|first3=Philip G.|last3=Janicak|title=Psychiatry: Diagnosis & therapy. A Lange clinical manual|isbn=978-0-8385-1267-8|publisher=Appleton & Lange (Original from Northwestern University)|year=1993|page=[https://archive.org/details/psychiatrydiagno00flah/page/217 217]|url=https://archive.org/details/psychiatrydiagno00flah/page/217|quote=The amount of time of sexual arousal needed to reach orgasm is variable—and usually much longer—in women than in men; thus, only 20–30% of women attain a coital climax. b. Many women (70–80%) require manual clitoral stimulation...}}</ref><ref name="Kenneth Mah">{{cite journal | first1 = Kenneth | last1 = Mah | first2 = Yitzchak M | last2 = Binik | title = The nature of human orgasm: a critical review of major trends | journal = [[Clinical Psychology Review]] | volume = 21 | issue = 6 | pages = 823–856 |date=7 January 2001 | pmid = 11497209| doi = 10.1016/S0272-7358(00)00069-6 | quote=Women rated clitoral stimulation as at least somewhat more important than vaginal stimulation in achieving orgasm; only about 20% indicated that they did not require additional clitoral stimulation during intercourse.}}</ref><ref name="Kammerer-Doak">{{cite journal | first1 = Dorothy | last1 = Kammerer-Doak | first2 = Rebecca G. | last2 = Rogers | title = Female Sexual Function and Dysfunction | journal = Obstetrics and Gynecology Clinics of North America | volume = 35 | issue = 2 | pages = 169–183 |date=June 2008 | pmid = 18486835 | doi = 10.1016/j.ogc.2008.03.006 | quote=Most women report the inability to achieve orgasm with vaginal intercourse and require direct clitoral stimulation ... About 20% have coital climaxes...}}</ref> Thick secretions called [[smegma]] collect around the clitoris.<ref name="ReferenceA"/>{{page needed|date=February 2016}}

The vaginal opening and the urethral opening are only visible when the labia minora are parted. These openings have many nerve endings that make them sensitive to touch. They are surrounded by a ring of sphincter muscles called the [[bulbocavernosus muscle]]. Underneath this muscle and on opposite sides of the vaginal opening are the vestibular bulbs, which help the vagina grip the penis by swelling with blood during arousal. Within the vaginal opening is the [[hymen]], a thin membrane that partially covers the opening in many [[Virginity|virgins]]. Rupture of the hymen has been historically considered the loss of one's virginity, though, by modern standards, loss of virginity is considered to be the first sexual intercourse. The hymen can be ruptured by activities other than sexual intercourse. The urethral opening connects to the bladder with the urethra; it expels urine from the bladder. This is located below the clitoris and above the vaginal opening.<ref name="ReferenceA"/>{{page needed|date=February 2016}}

The [[breast]]s are the subcutaneous tissues on the front thorax of the female body.<ref name="innerbody.com"/> Though they are not technically part of a woman's sexual anatomy, they do have roles in both sexual pleasure and reproduction.<ref name=Lehmiller>{{cite book |last=Lehmiller |first=Justin |date=2018 |title=The Psychology of Human Sexuality |edition=Second |pages=74–75 |url=https://books.google.com/books?id=JXJGDwAAQBAJ |publisher=John Wiley & Sons Ltd |isbn=9781119164739 }}</ref> Breasts are modified sweat glands made up of fibrous tissues and fat that provide support and contain nerves, blood vessels, and lymphatic vessels.<ref name="innerbody.com"/> Their [[Portal:Main|main]] purpose is to provide milk to a developing infant. Breasts develop during puberty in response to an increase in estrogen. Each adult breast consists of 15 to 20 milk-producing [[mammary glands]], irregularly shaped lobes that include [[alveolar gland]]s and a lactiferous duct leading to the nipple. The lobes are separated by dense connective tissues that support the glands and attach them to the tissues on the underlying pectoral muscles.<ref name="innerbody.com"/> Other connective tissue, which forms dense strands called suspensory ligaments, extends inward from the skin of the breast to the pectoral tissue to support the weight of the breast.<ref name="innerbody.com"/> Heredity and the quantity of fatty tissue determine the size of the breasts.<ref name="ReferenceA"/>{{page needed|date=February 2016}}

Men typically find female breasts attractive<ref>{{cite book |last=Buss |first=David |date=2019 |title=Evolutionary Psychology: The New Science of the Mind |edition=Sixth |chapter=Men's Long-Term Mating Strategies|url=https://books.google.com/books?id=Sn6JDwAAQBAJ |publisher=Routledge |isbn=9780429590061 }}</ref> and this holds true for a variety of cultures.<ref>{{cite journal |author=Jan Havlíček |author2=Vít Třebický |author3=Jaroslava Varella Valentova |author4=Karel Kleisner |author5=Robert Mbe Akoko |author6=Jitka Fialová |author7=Rosina Jash |author8=Tomáš Kočnar |author9=Kamila Janaina Pereira |author10=Zuzana Štěrbová |author11=Marco Antonio Correa Varella |author12=Jana Vokurková |author13=Ernest Vunan |author14=S Craig Roberts |title=Men's preferences for women's breast size and shape in four cultures |journal=Evolution and Human Behavior |date=2017|volume=38 |issue=2 |pages=217–226 |doi=10.1016/j.evolhumbehav.2016.10.002 |hdl=1893/24421 |hdl-access=free}}</ref><ref>{{cite journal |author=Barnaby J Dixson |author2=Paul L Vasey |author3=Katayo Sagata |author4=Nokuthaba Sibanda |author5=Wayne L Linklater |author6=Alan F Dixson |title=Men's preferences for women's breast morphology in New Zealand, Samoa, and Papua New Guinea |journal=Archives of Sexual Behavior |date=2011 |volume=40 |issue=6 |pages=1271–1279 |url=https://www.researchgate.net/publication/46404564 |doi=10.1007/s10508-010-9680-6|pmid=20862533 |s2cid=34125295}}</ref><ref>{{cite journal|author=Frank W. Marlowe |title=Mate preferences among Hadza hunter-gatherers|journal=Human Nature |date=2004|volume=15|issue=4|pages=365–376|url=https://www.unl.edu/rhames/courses/readings/Marlowe-hadza-mate-selection-criteria.pdf|doi=10.1007/s12110-004-1014-8|pmid=26189412|s2cid=9584357}}</ref> In women, [[stimulation of nipples|stimulation of the nipple]] seems to result in activation of the brain's genital sensory cortex (the same region of the brain activated by stimulation of the clitoris, vagina, and cervix).<ref>{{cite journal |author=Barry R Komisaruk |author2=Nan Wise |author3=Eleni Frangos |author4=Wen-Ching Liu |author5=Kachina Allen |author6=Stuart Brody |title=Women's clitoris, vagina, and cervix mapped on the sensory cortex: fMRI evidence|journal=The Journal of Sexual Medicine |date=2011|volume=8|issue=10|pages=2822–2830|pmc=3186818|pmid=21797981|doi=10.1111/j.1743-6109.2011.02388.x}}</ref> This may be why many women find nipple stimulation arousing and why some women are able to orgasm by nipple stimulation alone.<ref name=Lehmiller/>

=====Internal female anatomy=====
{{main|Female reproductive system}}

The female internal reproductive organs are the [[vagina]], [[uterus]], [[Fallopian tube]]s, and [[ovary|ovaries]]. The vagina is a sheath-like canal that extends from the vulva to the cervix. It receives the penis during intercourse and serves as a depository for sperm. The vagina is also the [[birth canal]]; it can expand to {{convert|10|cm|inch|abbr=on}} during labor and delivery. The vagina is located between the [[bladder]] and the [[rectum]]. The vagina is normally collapsed, but during [[sexual arousal]] it opens, lengthens, and produces lubrication to allow the insertion of the penis. The vagina has three layered walls; it is a self-cleaning organ with natural bacteria that suppress the production of yeast.<ref name="ReferenceA"/>{{page needed|date=February 2016}} The [[G-spot]], named after the [[Ernst Gräfenberg]] who first reported it in 1950, may be located in the front wall of the vagina and may cause orgasms. This area may vary in size and location between women; in some it may be absent. Various researchers dispute its structure or existence, or regard it as an extension of the clitoris.<ref name=Hines>{{cite journal |author=Hines T |date=August 2001 |title=The G-Spot: A modern gynecologic myth |journal=Am J Obstet Gynecol |volume=185 |issue=2 |pages=359–362 | doi=10.1067/mob.2001.115995  |pmid=11518892|s2cid=32381437 |url=https://semanticscholar.org/paper/59ac3e423b824c8b64b2359c10a496730cd2a656 }}</ref><ref name="Balon, Segraves">{{cite book|first1=Richard |last1=Balon |first2=Robert Taylor |last2=Segraves|title=Clinical Manual of Sexual Disorders |publisher= [[American Psychiatric Association|American Psychiatric Pub]]|year=2009|access-date=24 January 2014|page=258|isbn=978-1-58562-905-3|url={{Google books |plainurl=yes |id=YuP3Hb0TMLQC |}} }}</ref><ref name="Kilchevsky">{{cite journal|title=Is the Female G-Spot Truly a Distinct Anatomic Entity?|journal=[[The Journal of Sexual Medicine]]|volume= 9|date=January 2012 |pmid=22240236|doi=10.1111/j.1743-6109.2011.02623.x|lay-url=http://www.huffingtonpost.com/2012/01/19/g-spot-does-not-exist_n_1215822.html|lay-source=[[The Huffington Post]]|lay-date=19 January 2012 |last1=Kilchevsky |first1=A |last2=Vardi |first2=Y |last3=Lowenstein |first3=L |last4=Gruenwald |first4=I |issue=3|pages=719–726}}</ref>

The uterus or womb is a hollow, muscular organ where a fertilized egg (ovum) will implant itself and grow into a fetus.<ref name="ReferenceA"/>{{page needed|date=February 2016}} The uterus lies in the pelvic cavity between the bladder and the [[bowel]], and above the vagina. It is usually positioned in a 90-degree angle tilting forward, although in about 20% of women it tilts backwards.<ref name="innerbody.com"/> The uterus has three layers; the innermost layer is the [[endometrium]], where the egg is implanted. During ovulation, this thickens for implantation. If implantation does not occur, it is sloughed off during menstruation. The cervix is the narrow end of the uterus. The broad part of the uterus is the [[fundus (uterus)|fundus]].<ref name="ReferenceA"/>{{page needed|date=February 2016}}

During [[ovulation]], the ovum travels down the Fallopian tubes to the uterus. These extend about {{convert|4|inch|cm|spell=in}} from both sides of the uterus. Finger-like projections at the ends of the tubes brush the ovaries and receive the ovum once it is released. The ovum then travels for three to four days to the uterus.<ref name="ReferenceA"/>{{page needed|date=February 2016}} After sexual intercourse, sperm swim up this funnel from the uterus. The lining of the tube and its secretions sustain the egg and the sperm, encouraging [[fertilization]] and nourishing the ovum until it reaches the uterus. If the ovum divides after fertilization, [[identical twins]] are produced. If separate eggs are fertilized by different sperm, the mother gives birth to non-identical or [[fraternal twins]].<ref name="innerbody.com"/>

The ovaries (female gonads), develop from the same embryonic tissue as the [[testicles]]. The ovaries are suspended by ligaments and are the source where ova are stored and developed before ovulation. The ovaries also produce female hormones [[progesterone]] and [[estrogen]]. Within the ovaries, each ovum is surrounded by other cells and contained within a capsule called a primary follicle. At puberty, one or more of these follicles are stimulated to mature on a monthly basis. Once matured, these are called [[Graafian follicles]].<ref name="ReferenceA"/>{{page needed|date=February 2016}} The female reproductive system does not produce the ova; about 60,000 ova are present at birth, only 400 of which will mature during the woman's lifetime.<ref name="innerbody.com"/>

Ovulation is based on a monthly cycle; the 14th day is the most fertile. On days one to four, menstruation and production of estrogen and progesterone decreases, and the endometrium starts thinning. The endometrium is sloughed off for the next three to six days. Once menstruation ends, the cycle begins again with an FSH surge from the pituitary gland. Days five to thirteen are known as the pre-ovulatory stage. During this stage, the pituitary gland secretes [[follicle-stimulating hormone]] (FSH). A negative feedback loop is enacted when estrogen is secreted to inhibit the release of FSH. Estrogen thickens the endometrium of the uterus. A surge of [[Luteinizing Hormone]] (LH) triggers ovulation.

On day 14, the LH surge causes a Graafian follicle to surface the ovary. The follicle ruptures and the ripe ovum is expelled into the abdominal cavity. The fallopian tubes pick up the ovum with the [[Fimbriae of uterine tube|fimbria]]. The cervical mucus changes to aid the movement of sperm. On days 15 to 28—the post-ovulatory stage, the Graafian follicle—now called the [[corpus luteum]]—secretes estrogen. Production of progesterone increases, inhibiting LH release. The endometrium thickens to prepare for implantation, and the ovum travels down the Fallopian tubes to the uterus. If the ovum is not fertilized and does not implant, menstruation begins.<ref name="ReferenceA"/>{{page needed|date=February 2016}}