During menstruation, where do estrogen and progesterone primarily occur?

During menstruation, estrogen and progesterone primarily play crucial roles in the reproductive cycle, particularly in the endometrium, which is the inner lining of the uterus. The endometrium undergoes significant changes in response to these hormones, preparing it for potential implantation of a fertilized egg.

During the menstrual cycle, after ovulation, the corpus luteum forms and produces both estrogen and progesterone. These hormones are essential to maintain the thickened state of the endometrium in case of pregnancy. If fertilization does not occur, hormone levels drop, leading to the shedding of the endometrial lining, which is experienced as menstruation.

While the corpus luteum is indeed responsible for the production of these hormones post-ovulation, the question specifically asks where these hormones primarily exert their effects, which is in the endometrium where they influence the menstrual cycle. The myometrium, which is the muscular layer of the uterus, and the ovaries, where the follicles develop, are not the primary sites of hormonal action in relation to menstruation. Thus, the focus on the endometrium accurately reflects the primary physiological context of estrogen and progesterone during this phase.