How Does the Functional Layer Change During the Menstrual Cycle?
The functional layer undergoes significant changes during the menstrual cycle:
1. Proliferative Phase: Following menstruation, the functional layer regenerates from the basal layer. Estrogen stimulates the proliferation of epithelial cells, stromal cells, and blood vessels.
2. Secretory Phase: After ovulation, progesterone from the corpus luteum induces the glands to secrete nutrients and the stroma to become edematous, preparing the endometrium for potential implantation.
3. Menstrual Phase: If implantation does not occur, the corpus luteum regresses, leading to a drop in hormone levels. This causes the functional layer to shed, resulting in menstruation.
