Luteal or Secretory Phase

During the luteal (or secretory) phase, which follows ovulation, the remaining cells of the ruptured Graafian follicle reorganise into a new, short-lived endocrine structure called the corpus luteum. The corpus luteum secretes large amounts of progesterone, which is essential for maintaining the endometrium in a thick, nutrient-secreting state — hence the phase's alternative name, the secretory phase, since the uterine wall is actively secreting a nutritious fluid in readiness for a possible embryo. If fertilisation has occurred, this support continues and menstruation is held off entirely for the duration of pregnancy. If it has not, the corpus luteum degenerates completely, leaving behind a small patch of scar tissue called the corpus albica …