Question

In a normal human female, why does menstruation only occur if the released ovum is not fertilised? Explain.

Hint:

The degeneration of the corpus luteum after unfertilized cycles leads to menstruation, resetting the reproductive system.

Answer 1

- If the ovum is not fertilised, the corpus luteum degenerates, leading to a drop in progesterone levels. 
- This drop causes the breakdown of the thickened uterine lining, resulting in its shedding as menstrual blood.