Menstruation

In women, menstruation means the monthly rejection of the uterine function with the ovum that has remained unfertilised. A new Graaf follicle is then formed and passed from the ovaries to the [[fallopian tubes], in the upper part of which it waits for fertilisation.

https://de.wikipedia.org/wiki/Menstruation _{(Wikipedia CC-by-sa-3.0)}