The menstrual cycle is divided into several distinct phases: 1. Follicular Phase: FSH promotes follicular growth in the ovaries. The dominant follicle starts producing estrogen. 2. Ovulation: A surge in LH levels triggers the release of a mature egg from the dominant follicle. 3. Luteal Phase: The ruptured follicle transforms into the corpus luteum, which secretes progesterone to prepare the endometrium for potential implantation. 4. Menstruation: If fertilization does not occur, the corpus luteum degenerates, leading to a drop in progesterone and estrogen levels, resulting in the shedding of the endometrial lining.
