The breakdown of the corpus luteum causes menstruation in the menstrual cycle.
The breakdown of the corpus luteum is responsible for causing menstruation. The corpus luteum, which forms after the release of the egg during ovulation, produces progesterone to maintain the endometrium. If the egg is not fertilized, the corpus luteum degenerates, progesterone levels drop, and the endometrium sheds, resulting in menstruation.
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