What determines the menstrual cycle?

Patient's question:

No

Doctor's answer:

Menstruation is the periodic shedding of the endometrium, resulting in bleeding that is expelled through the vagina during a woman's reproductive life. Approximately every month, the endometrium undergoes a cyclical process of thickening, vascular proliferation, glandular growth and secretion, as well as necrosis and shedding of the endometrium accompanied by bleeding. This physiological cycle is known as the menstrual cycle.