Answer
The shedding of stratum functionalis of the uterine ling takes place during days 1-5 of the menstrual cycle if there is no fertilized oocyte implanted in the endometrium. At this time both FSH and LH secretions are low and consequently serum level of estrogen is low, and that of progesterone is lower still. The next phase in the menstrual cycle is the proliferation phase. In this phase the basal layer of the endometrium regrows the functional layer in preparation for a possible fertilization and implantation in the next menstrual cycle. In this progesterone is still low but estrogen rises slowly. During the proliferative phase ( days 6-14) the endometrium becomes thick and vascularized; progesterone receptors are synthesized and the glands of the mucosa secrete thick mucus. To facilitate sperm passage this mucus thins toward the end of this phase. Ovulation takes place at about Day 14 in the cycle when the endometrium is thick and secretory, in preparation for nourishing a fertilized oocyte, or zygote.
Work Step by Step
The shedding of stratum functionalis of the uterine ling takes place during days 1-5 of the menstrual cycle if there is no fertilized oocyte implanted in the endometrium. At this time both FSH and LH secretions are low and consequently serum level of estrogen is low, and that of progesterone is lower still. The next phase in the menstrual cycle is the proliferation phase. In this phase the basal layer of the endometrium regrows the functional layer in preparation for a possible fertilization and implantation in the next menstrual cycle. In this progesterone is still low but estrogen rises slowly. During the proliferative phase ( days 6-14) the endometrium becomes thick and vascularized; progesterone receptors are synthesized and the glands of the mucosa secrete thick mucus. To facilitate sperm passage this mucus thins toward the end of this phase. Ovulation takes place at about Day 14 in the cycle when the endometrium is thick and secretory, in preparation for nourishing a fertilized oocyte, or zygote.
