Editing Human sexual activity (section)

==Stages of physiological arousal during sexual stimulation==
{{main|Human sexual response cycle}}
The physiological responses during [[sexual stimulation]] are fairly similar for both men and women and there are four phases.<ref name="Schacter">{{cite book |author1=Daniel L. Schacter |author2=Daniel T. Gilbert |author3=Daniel M. Wegner| title =Psychology| publisher =[[Macmillan Publishers|Macmillan]]|year = 2010|pages=335–336|access-date = 10 November 2012| isbn = 978-1429237192|url =https://books.google.com/books?id=emAyzTNy1cUC&q=Men%20and%20women%20may%20have%20different%20levels%20of%20sexual%20drive%2C%20but%20their%20physiological%20responses%20during%20sex%20are%20fairly%20similar.&pg=PA335}}</ref>
* During the excitement phase, muscle tension and blood flow increase in and around the sexual organs, heart and respiration increase and blood pressure rises. Men and women experience a "[[sex flush]]" on the skin of the upper body and face.  For women, the [[vagina]] becomes [[vaginal lubrication|lubricated]] and the [[clitoris]] engorges.<ref name="Schacter"/> For men, the [[human penis|penis]] becomes [[erection|erect]].
* During the plateau phase, heart rate and muscle tension increase further. A man's urinary bladder closes to prevent urine from mixing with [[semen]]. A woman's clitoris may withdraw slightly and there is more lubrication, outer swelling and muscles tighten and reduction of diameter.<ref name="Schacter"/>
* During the [[orgasm]] phase, breathing becomes extremely rapid and the pelvic muscles begin a series of rhythmic contractions. Both men and women experience quick cycles of muscle contraction of lower pelvic muscles and women often experience uterine and vaginal contractions; this experience can be described as intensely pleasurable, but roughly 15% of women never experience orgasm, and half report having [[Fake orgasm|faked it]].<ref name="Schacter"/> A large genetic component is associated with how often women experience orgasm.<ref name="Schacter"/>
* During the resolution phase, muscles relax, blood pressure drops, and the body returns to its resting state. Though generally reported that women do not experience a [[Refractory period (sex)|refractory period]] and thus can experience an additional orgasm, or multiple orgasms soon after the first,<ref name="Rosenthal">{{cite book |first=Martha |last= Rosenthal| title = Human Sexuality: From Cells to Society | publisher =[[Cengage Learning]]|year = 2012|pages=134–135|access-date = 17 September 2012| isbn = 9780618755714 |url =https://books.google.com/books?id=d58z5hgQ2gsC&pg=PT154 }}</ref><ref name=SOC>{{cite web| title = The Sexual Response Cycle| publisher = [[University of California, Santa Barbara]] | url = http://www.soc.ucsb.edu/sexinfo/article/the-sexual-response-cycle|access-date =6 August 2012|archive-url=https://web.archive.org/web/20110725051823/http://www.soc.ucsb.edu/sexinfo/article/the-sexual-response-cycle|archive-date=25 July 2011}}</ref> some sources state that both men and women experience a refractory period because women may also experience a period after orgasm in which further sexual stimulation does not produce excitement.<ref name="Schacter"/><ref name="Weiner & Craighead">{{cite book |author1=Irving B. Weiner |author2=W. Edward Craighead | title = The Corsini Encyclopedia of Psychology, Volume 2 | publisher =[[John Wiley & Sons]]|year = 2010|page=761|access-date = 10 November 2012| isbn = 978-0470170267|url = https://books.google.com/books?id=pa5vKqntwikC&pg=PA761}}</ref> This period may last from minutes to days and is typically longer for men than women.<ref name="Schacter"/>

[[Sexual dysfunction]] is the inability to react emotionally or physically to sexual stimulation in a way projected of the average healthy person; it can affect different stages in the sexual response cycles, which are desire, excitement and orgasm.<ref>Kontula, O & Mannila, E (2009). Sexual Activity and Sexual Desire. Routledge, 46(1). retrieved 20 August 2012, from [http://bf4dv7zn3u.search.serialssolutions.com/?ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info:sid/summon.serialssolutions.com&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=The+Impact+of+Aging+on+Human+Sexual+Activity+and+Sexual+Desire&rft.jtitle=Journal+of+Sex+Research&rft.au=Haavio-Mannila%2C+Elina&rft.au=Kontula%2C+Osmo&rft.date=2009-02-03&rft.pub=Taylor+%26+Francis+Group%2C+LLC&rft.issn=0022-4499&rft.volume=46&rft.issue=1&rft.spage=46&rft.epage=56&rft_id=info:doi/10.1080%2F00224490802624414&rft.externalDBID=PJSX&rft.externalDocID=196534090 here.]</ref> In the media, sexual dysfunction is often associated with men, but in actuality, it is more commonly observed in females (43 percent) than males (31 percent).<ref>{{cite journal |last1=Jha |first1=S. |last2=Thakar |first2=R. | year = 2010 | title = Female sexual dysfunction | journal = European Journal of Obstetrics & Gynecology and Reproductive Biology | volume = 153 | issue = 2| pages = 117–123 | doi = 10.1016/j.ejogrb.2010.06.010 | pmid = 20678854 |issn = 0301-2115 }}</ref>