Why does a drop in estrogen cause menstrual bleeding, but you don’t bleed during menopause?

Question

As I understand it, (which is why I’m asking because I’m sure I’m missing something), the bleeding phase of a menstrual cycle is triggered by lowered estrogen levels. So, low estrogen = bleeding. Why then, in menopause, which is characterized by low estrogen, do women not bleed 24/7 for the rest of their lives?

In the same vein, why is perimenopause associated with skipping bleeding phases rather than having more constant bleeding?

In: Biology

Answer 1

The whole period cycle starts because the utherus prepares an egg for impregnation, and then expels it with the utherus’ tissue when it doesn’t get impregnated, causing bleeding. A woman in menopause doesn’t have any egg prepared, so there’s no bleeding.