The secretory phase in the human menstrual cycle is also called:

Explanation

After ovulation which occurs in the middle of the menstrual cycle, the empty Graafian follicle continues growth under the influence of LH. The follicular cells are converted into lutein cells by deposition of yellowish lipid inclusions. The phenomenon is called luteinization. The ruptured Graafian follicle is now called the corpus luteum. It secretes hormones, mainly progesterone and a small quantity of estrogen. Both LH and progesterone help in further growth and thickening of endometrium. The major change is that the endometrial glands become secretory. The uterine wall becomes ready for nourishing and anchoring blastocyst if fertilization takes place. Hence, this phase of the menstrual cycle is called the luteal or secretory phase. The phase lasts for about 13 days.