[i]Not to be confused with [[defloration]][/i]

Menstruation is the shedding of the uterine lining (endometrium). It occurs on a regular basis in reproductive-age females of certain mammal species. Overt menstruation (where there is [[bleeding]] from the [[uterus]] through the [[pussy]]) is found primarily in humans and close evolutionary relatives such as chimpanzees. 

h4. See also

* [[tampon]]
** [[tampon string]]
* [[menstrual pad]]
生理