How do Hormonal Levels Fluctuate During the Menstrual Cycle?
The menstrual cycle is divided into several phases: follicular, ovulation, luteal, and menstruation. Each phase is characterized by distinct hormonal changes:
During the follicular phase, FSH stimulates the growth of ovarian follicles, which produce estrogen. At ovulation, a surge in LH triggers the release of an egg from the dominant follicle. In the luteal phase, the ruptured follicle forms the corpus luteum, which secretes progesterone and some estrogen. If pregnancy does not occur, the corpus luteum degenerates, leading to a drop in progesterone and estrogen, resulting in menstruation.
