Notes on FSH and LH

Back to the main reproduction page

FSH and LH from the pituitary:



In Females

In Males

FSH Controls

Eggs + Estrogen


LH Controls

Ovulation + Corpus Luteum


In females:

1) FSH (follicle stimulating Hormone)

A) Causes Egg maturation: Stimulates maturation of follicle and ova.




B) Stimulates follicle to produce Estrogen


Estrogen is responsible for the following:



1) Overall female characteristics



2) Changes at puberty (breasts, hips, hair)



3) (Repair after menstruation) thickening of uterine lining.


2) LH (luteinizing Hormone)

A)    Causes follicle to burst and ova to leave (ovulation) fertilization in 12-24 hours!


B) Causes the follicle to turn into the corpus luteum



The corpus luteum makes....

1) Progesterone (the hormone of pregnancy)


a) Progesterone promotes nutrition secretion from oviduct walls


b) Progesterone quiets uterus


c) Progesterone promotes development of ducts in breasts


d) Progesterone promotes growth of endometrium



2) More Estrogen


Progesterone and Estrogen:


1) P and E Cause further growth of endometrium

2) P and E increase blood supply to uterus and endometrium

3) P and E inhibit FSH and LH - prevents maturation of other ova.

The embryo is responsible for making a hormone similar to LH that maintains the corpus luteum. The corpus luteum only lasts 10 to 12 days. The corpus luteum provides the progesterone and estrogen that maintain the developing embryo.

Later, the placenta produces progesterone and estrogen and the corpus luteum is no longer needed.

If the egg is not fertilized, no implantation occurs, and the embryo does not make LH. Thus, the corpus luteum regresses, (it only lasts 10-12 days) and levels of progesterone fall allowing menstruation to occur.

In males:

FSH regulates the development of sperm.

LH stimulates the production of Androgens (testosterone)

Back to the main reproduction page