Prab at 14:07, 19 March 2025

2025-03-19T14:07:37Z

Prab at 16:01, 17 September 2020

2020-09-17T16:01:46Z

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[[File:Weibliche brust en.jpg|thumb|Female human breasts]]

The '''breast''' is an organ on the lower chest region of humans and other [[primate]]s. Humans have two breasts. Both boys and girls have breasts at birth, but during [[puberty]], the breasts on women become larger and visible. The breasts have [[mammary gland]]s that produce milk. [[Breastfeeding]] is letting an [[infant]] drink breast [[milk]].

== Male breast ==
Men also have breasts. They are built the same way as those of women but are much smaller and [[underdeveloped]]. Men cannot use their breast for breastfeeding. Their breasts will usually not produce milk, but might become larger and produce milk during some diseases or with some [[hormone|hormonal]] medical treatments.<ref>''Introduction to the Human Body, fifth ed.'' John Wiley & Sons, Inc.: New York, 2001. '''560'''.</ref>

== Growth and form ==
Girls develop breasts during [[puberty]] due to [[sex hormone]]s, mainly [[estrogen]].

The appearance and size of the breasts of a woman may vary due to [[genetics|genetic]] factors, and the amount of [[fat]]ty and [[connective tissue]].<ref>{{cite web | url=http://www.afraidtoask.com/?page_id=119 | title=Size and Shape | publisher=afraidtoask.com | accessdate=30 July 2010}}</ref> [[Hormone]]s also play a role.<ref name="Ohio State">{{cite web | url=http://medicalcenter.osu.edu/patientcare/healthcare_services/breast_health/normal_breast_development/Pages/index.aspx | title=Normal Breast Development | publisher=The Ohio State University Medical Center | accessdate=30 July 2010}}</ref>

Estrogen promotes the growth of mammary glands and ducts, while progesterone induces milk-producing cells to develop. Prolactin and oxytocin stimulate milk production. Oxytocin also causes milk to be spurted from a lactating breast.<ref>{{cite web | url=http://www.herballove.com/article.asp?art=207 | title=Breast Anatomy & Physiology — Lactation | last=Perez | first=Jane | publisher=Herballove.com | accessdate=30 July 2010}}</ref>

The two breasts usually are not equal in size — one may be larger than the other, but this is common.<ref>{{cite web | url=http://www.wdxcyber.com/nbreast3.htm | title=Breast Asymmetry - When Does It Need Treatment? | last=Jelovsek | first=Frederick R. | publisher=wdxcyber.com | accessdate=30 July 2010}}</ref>

During [[menopause]], as levels of estrogen decrease, tissue in the breasts reduce as well, and the breasts may start sagging.<ref name="Ohio State"/> A study showed that breastfeeding does not cause sagging. Factors that do influence sagging are the size of the breast (before the first pregnancy), number of pregnancies, [[body mass index]], [[smoking]], and age.<ref>{{cite web | url=http://www.plasticsurgery.org/media/press_releases/Breastfeeding-Does-Not-Create-Sagging-Breasts.cfm | title=Breastfeeding Does Not Create Sagging Breasts; Study Throws Out Old Wives' Tale | archiveurl=https://web.archive.org/web/20080503222456/http://plasticsurgery.org/media/press_releases/Breastfeeding-Does-Not-Create-Sagging-Breasts.cfm |archivedate=30 July 2010}}</ref>

== Structure ==
[[File:Cassatt Mary Maternite 1890.jpg|thumb|A woman breast-feeding her child; image painted by [[Mary Cassatt]], [[1890]]]]

The center of the breast is the [[nipple]]. The [[areola]] is a circular area around the nipple. The breast contains mammary glands. Each breast has 15 to 20 milk ducts.<ref>{{Cite web|url=https://www.ncbi.nlm.nih.gov/books/NBK430938/#_NBK430938_pubdet_|title=Sajadi-Ernazarova KR, Adigun R. Breast, Nipple Discharge.|last=|first=|website=|publisher=National Center for Biotechnology Information, U.S. National Library of Medicine|publication-date=16 October 2017|archive-url=|archive-date=|dead-url=|access-date=|postscript=; This work is distributed with https://creativecommons.org/licenses/by/4.0/ (CC BY 4.0)}}</ref> Ducts carry the [[milk]] produced by these glands to the nipples. After a woman has a [[baby]], her breasts undergo lactation — the production of natural milk.

Feeding babies milk is called [[breastfeeding]] or ''nursing''.<ref>{{cite web | url=http://www.oncologychannel.com/breastcancer/breastanatomy.shtml | title=Breast Anatomy|publisher=Healthcommunities.com | accessdate=30 July 2010}}</ref>

== Purposes ==
The breasts of a woman also play a role in human sexual behaviour. They are one of the most visible or obvious female [[secondary sex characteristic]]s.<ref>[http://www2.hu-berlin.de/sexology/ATLAS_EN/html/secondary_characteristics.html secondary sex characteristics]</ref> They play an important role in [[sexual attraction]] of partners. They can also give pleasure to the individual. When sexually stimulated, the size of the breasts increases, [[vein|venous]] patterns across the breasts become more visible, and nipples grow harder. During sexual intercourse, it is common practice to press or massage breasts with hands. Breasts are sensitive to touch as they have many nerve endings.<ref>"The entire breast is a network of nerve endings" [http://kenyanflavour.com/home/index.php?option=com_content&task=view&id=7&Itemid=32 link]</ref> [[Oral stimulation of nipples]] and breasts is also common. Some women can achieve "breast [[orgasm]]s". In the [[ancient India]]n work the ''[[Kama Sutra]]'', marking breasts with nails and biting with teeth are explained as erotic.<ref>[http://www.sacred-texts.com/sex/kama/index.htm Sir Richard Burton's English translation of Kama Sutra]</ref>

==Related pages==
* [[Breast augmentation]]
* [[Breast reduction]]

== References ==
{{reflist|2}}

==External links==
{{Wiktionary|breasts}}
{{Commons category|Breasts}}
{{Wikiquote}}
{{Wikibooks|Radiation Oncology/Breast}}
{{Wikisource|1911 Encyclopædia Britannica/Breast}}
* {{cite web |archiveurl = https://web.archive.org/web/20111202170751/http://www.nyu.edu/fas/ihpk/CultureMatters/Mascia-Lees.htm |title = Are Women Evolutionary Sex Objects?: Why Women Have Breasts |archivedate = 2 December 2011 |url = http://www.nyu.edu/fas/ihpk/CultureMatters/Mascia-Lees.htm }}
{{Breast navs}}
{{Breast anatomy}}
{{Disorders of the breast}}
{{Sex}}
{{Authority control}}

[[Category:Breast| ]]
[[Category:Breastfeeding]]
[[Category:Human sexuality]]

Breast - Revision history

Prab at 14:07, 19 March 2025

Prab at 16:01, 17 September 2020