Prompt, that occurs or happens in genital organs of the woman before a menses...

[Svetlana]

Prompt, what occurs or happens in genital organs of the woman before a menses if conception has not occured or happened? Thanks

[popenko. Century]

There is an involution of a yellow body, a casting-off endometrija. With the beginning of a menses - a new cycle.

[Kamenetskij B.A.]

First of all this depression of a level of some hormones and, as consequence or investigation, a casting-off of a mucous uterus (endometrija) t. e. A menses.