View source for Cyclical changes in the female body

=== Menstrual bleeding ===
The duration of menstrual bleeding, like the entire menstrual cycle, is an individual matter, but on average it is '''3-5 days'''. It is terminated by vasoconstriction of the supply arterioles in the [[myometrium]]. The amount of menstrual blood is about '''40–50 ml'''. It is a mixture of arterial and venous blood, mucus, tissue fluid with parts of autolyzed mucosa. Enzymes released during the breakdown of mucous cells ('''plasmin''') prevent menstrual blood from clotting.