Question

What are the functions of FSH and LH during the female reproductive cycle? What hormone spikes to a high level, inducing ovulation?

Answer 1

FSH (follucular stimulating hormone ) is produced and secreted from the Anterior pituitary gland.

FSH hormone help in the proliferation of the follicular cell of the ovary.

In the ovulatory cycle, FSH mainly produced in the Follicular phase, in which it help in the proliferation of primary follicle to secondary follicle then into tertiary follicle then to matured follicle (graffian follicle)

The other function of the FSH is that it stimulate the Ovary to secrete estrogen hormone.

Estrogen role in ovulatory phase is that , it help to increase the LH (leutinising hormone) production from the Anterior pituitary gland.

This LH hormone reaches a peak during the Ovulation phase ( 14th day of ovulatory cycle) .This surge in the LH hormone stimulate the matured(graffian follicle to release the secondary oocyte.

LH also help in the conversion of Graffian follicle to corpus luteum . This occur after the ovulation and this phase is called Luteal phase.

Corpus luteum produce progesterone hormone that help in the mainainence of endometrium for the implantation.

if the egg is fertilised, the LH hormone secretion get stopped and this function is taken up by the HCG hormone from the placenta .

If egg is not fertilised, the progesterone and estrogen level falls and it send a signak to the hypothalamus for the release of Gonadotrophin releasing hormone (negative feedback mechanim) it further produce LH and FSH from the anterior pituitary gland.This cycle will continue.