Menstrual Cycle Shedding and Cramps

The menstrual phase is the first stage of the uterine cycle. It is counted as day one of the cycle and usually lasts about five days. During this time, the uterine lining sheds its functional layer, called the stratum functionalis.

If fertilization does not occur, the corpus luteum breaks down. T...

The menstrual cycle starts with the menstrual phase, with its first day considered Day 1 of the cycle.

This phase usually lasts for 1 to 5 days and is characterized by the degeneration and shedding of the endometrial functional layer, or stratum functionalis.

The lack of fertilization leads to degeneration of the corpus luteum, dec...