Question

correct hormonal sequence in the case of menstruation as
A) Oestrogen,FSH, progesterone
B) Oestrogen, progesterone, FSH
C) FSH, Progesteron, oestrogen
D) FSH, oestrogen, progesterone

Answer 1

Hint:Menstruation cycle is the reproductive cycle in all primates. It begins at puberty which is called menarche. The whole cycle takes around 28 or 29 days to complete. The end of cycle is accompanied by the breakdown of uterine mucus till the next that takes place during the reproductive period.

Complete answer:
FSH, oestrogen and progesterone regulate the menstrual cycle.In follicular phase the release of gonadotropins ( FSH and LH) from anterior pituitary gland increases. Primary follicles develop in to graafian follicles. These graafian follicles secretes estrogen. Estrogen inhibits the secretion of FSH and stimulates the secretion of LH. It also causes thickening of the uterine endometrium. High levels of progesterone hormone in the blood decreases the secretion of LH and FSH , therefore inhibiting further ovulation.

Follicle stimulating hormone is responsible for the development of egg and causing the levels of oestrogen to rise. Pituitary produce luteinizing hormone that aids in egg maturation and provides the hormonal triggers to cause ovulation and release of eggs from the ovary.

During pregnancy all events of the menstrual cycle stops and there is no menstruation. In the absence of fertilization , corpus luteum degenerates and becomes a whitish mass called corpus albicans. Since it has no secretory ability , progesterone level in blood decreases. It leads to menstruation indicating a new cycle.

Hence, the correct answer is option ‘D’.

Note: During pregnancy , the level of estrogen, progestogen, cortisol, prolactin, thyroxine etc also increased in maternal blood. They support the fetal growth , metabolic changes in the mother and maintain pregnancy.