Explanation:
From the first day, the 3 phases of the uterine cycle, in order are:
1. Follicular Phase or Preovulatory Phase: Growth of follicles. In this phase, the follicle stimulating hormone (FSH) increases, which stimulates the growth and recruitment of immature ovarian follicles in the ovary, and goes from the onset of menstruation to ovulation.
2. Ovulatory Phase: Around day 14 of the menstrual cycle, the pituitary gland produces a rise in luteinizing hormone (LH) levels, which is known as the LH peak that triggers ovulation. The mature egg is released by the fallopian tube.
3. Luteal Phase or Postovulatory Phase: Starts once ovulation occurs and lasts until the end of the menstrual cycle. It results in the formation of the Luteo body responsible for producing estrogen and progesterone that will act on the endometrium.
