* Overt menstruation, occuring in [[human]]s and [[great apes]], in which the lining of the [[uterus]] is shed and expelled from the body to prepare the uterus for a fertilized [[ovum]]<ref>[http://www.4woman.gov/faq/menstru.htm#4 Menstruation and the Menstrual Cycle, from the US Dept. of Health and Human Services]</ref>; | * Overt menstruation, occuring in [[human]]s and [[great apes]], in which the lining of the [[uterus]] is shed and expelled from the body to prepare the uterus for a fertilized [[ovum]]<ref>[http://www.4woman.gov/faq/menstru.htm#4 Menstruation and the Menstrual Cycle, from the US Dept. of Health and Human Services]</ref>; |