Editing Uterus (section)

== Function ==
[[File:Human female inner genitalia.png|thumb|Maximum penetration depth of the penis]]
The primary reproductive function of the human uterus is to prepare for the implantation of a [[zygote]], a fertilized [[Egg cell|ovum]], and maintenance of pregnancy if implantation occurs.<ref name="Critchley-2020">{{Cite journal |last1=Critchley |first1=Hilary O. D. |last2=Maybin |first2=Jacqueline A. |last3=Armstrong |first3=Gregory M. |last4=Williams |first4=Alistair R. W. |date=2020-07-01 |title=Physiology of the Endometrium and Regulation of Menstruation |journal=Physiological Reviews |language=en |volume=100 |issue=3 |pages=1149–1179 |doi=10.1152/physrev.00031.2019 |pmid=32031903 |s2cid=211063583 |issn=0031-9333|doi-access=free |hdl=20.500.11820/36236a4e-a35e-4818-abe3-5d8b278c66f8 |hdl-access=free }}</ref> Traveling along the [[fallopian tube]] on its way to the uterine cavity, the zygote divides [[mitosis|mitotically]] to become a [[blastocyst]], which ultimately attaches to the uterine wall and  [[Implantation (embryology)|implants]] into the [[endometrium]].<ref name="openstax" /> The [[placenta]] later develops to nourish the embryo, which grows through [[human embryonic development|embryonic]] and [[prenatal development|fetal development]] until [[childbirth]]. During this process, the uterus grows to accommodate the growing fetus.<ref name="Ameer-2023">{{Citation |last1=Ameer |first1=Muhammad Atif |title=Anatomy, Abdomen and Pelvis: Uterus |date=2023 |url=http://www.ncbi.nlm.nih.gov/books/NBK470297/ |work=StatPearls |access-date=2023-10-30 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=29262069 |last2=Fagan |first2=Sarah E. |last3=Sosa-Stanley |first3=Jessica N. |last4=Peterson |first4=Diana C.}}</ref> When normal labor begins, the uterus forcefully contracts as the cervix dilates, which results in delivery of the infant.<ref name="Ameer-2023" />

In the absence of pregnancy, [[menstruation]] occurs.<ref name="Critchley-2020" /> The withdrawal of female sex hormones, [[estrogen]] and [[progesterone]], which occurs in the absence of fertilization, triggers the shedding of the functional layer of the endometrium.<ref name="Critchley-2020" /> This layer is broken down, shed, and restored in anticipation of the next menstrual cycle.<ref name="Critchley-2020" /> The average bleeding duration during menses is 5-7 days after which the menstrual cycle begins again.<ref>{{Citation |last1=Thiyagarajan |first1=Dhanalakshmi K. |title=Physiology, Menstrual Cycle |date=2023 |url=http://www.ncbi.nlm.nih.gov/books/NBK500020/ |work=StatPearls |access-date=2023-10-30 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=29763196 |last2=Basit |first2=Hajira |last3=Jeanmonod |first3=Rebecca}}</ref>