Changes

===Inhibin===

===Inhibin===

Inhibin is a type of glycoprotein that is synthesised within the granulosa cells in females and in sertoli cells in the male. In both males and females the target organ for inhibin is the anterior pituitary, specifically the gonadotroph cells. In the male inhibin inhibits FSH secretion, which together with decreased concentrations of LH and testosterone results in decreased spermatogenesis and therefore decreased sperm output and quality.  

Inhibin is a type of glycoprotein that is synthesised within the granulosa cells of ovarian follicles in females and in sertoli cells located in the seminiferous tubules within the testes in the male. In both males and females the target organ for inhibin is the anterior pituitary, specifically the gonadotroph cells.  

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In females inhibin stimulates FSH secretion. When inhibin is secreted a relatively higher concentration of LH is secreted from the anterior pituitary gland than FSH. Therefore during follicle development, the increased LH concentration causes cessation of the recruitment of further follicles under the effect of FSH. The hormonal changes resulting from the production of inhibin cause some of the previously recruited follicles to undergo atresia.

In females some studies have suggested that inhibin may also be produced by the placenta. In females inhibin stimulates FSH secretion. When inhibin is secreted, a relatively higher concentration of LH is secreted from the anterior pituitary gland than FSH. Therefore during follicle development, the increased LH concentration causes cessation of the recruitment of further follicles under the effect of FSH. The hormonal changes resulting from the production of inhibin cause some of the previously recruited follicles to undergo atresia. Inhibin in the female can also be diminished by GnRH and enhanced by insulin-like growth factor-1 (IGF-1).

===Activin===

===Activin===