Question

Discuss hormonal factors involved in the maturation of an ovum, ovulation and formation and maintenance of the corpus luteum during a normal menstrual cycle

Answer 1

Follicular stimulating hormone (FSH) stimulates development of egg cells called ova, which develop in structures called follicles and these follicle cells produce the hormone inhibin which inhibits FSH production.Leutinzing hormone(LH) also plays a role in the development of ova by induction of ovulation, and stimulation of estradiol and progesterone production by the ovaries.

The ovarian cycle governs the preparation of endocrine tissues and release of eggs and menstrual cycle governs the preparation and maintenance of the uterine lining.

In the first half of the ovarian cycle is the follicular phase the slow rise in the level of FSH and LH cause the growth of follicles on the surface of the ovary and prepares the egg for ovulation.  The follicles grow and they begin releasing estrogens and a low level of progesterone. If pregnancy implantation does not occur, the lining is sloughed off and ad after about 5 days the estrogen level rise and the menstrual cycle enters the proliferative phase and the endometrium begins to regrow, replacing the blood vessels and glands that deteriorated during the end of the last cycle.Prior to the middle of the cycle,a high level of estrogen causes FSH and LH to rise rapidly, then fall and this spike in LH causes ovulation and the level of estrogen decreases when the extra follicles degenerates. Then the ovarian cycle enters its luteal phase and the menstrual cycle enters its secretory phase.The luteal and secretory phases refer to changes in the ruptured follicle and the cells in the follicle undergo physical changes and produce a structure called a corpus luteum which produces estrogen and progesterone.The progesterone facilitates the regrowth of the uterine lining and inhibits the release of further FSH and LH and the uterus is being prepared to accept a fertilized egg.The inhibition of FSH and LH prevents any further eggs and follicles from developing, while the progesterone is elevated and the level of estrogen produced by the corpus luteum increases.

If no fertilized egg is implanted into the uterus, the corpus luteum degenerates and the levels of estrogen and progesterone decrease and the endometrium begins to degenerate as the progesterone levels drop by initiating the next menstrual cycle.The decrease in progesterone allows the hypothalamus to send GnRH to the anterior pituitary and releases FSH and LH and starts the cycles again.

Hope this helps you. Thank you ?