Regulation of the testis

Regulation of the testis

Gonadotropin-releasing hormone from the hypothalamus is released in the portal system in order to reach the gonadotropic cells in the pituitary. Upon stimulation, these cells release FSH and LH. The Leydig cells in the testis carry receptors for LH. LH promotes the production of testosterone in these cells. Testosterone serves three main functions: it stimulates Sertoli cells and, when present in the bloodstream it has a negative feedback on GnRH and LH secretion and it serves general functions such as development

of secondary sex characteristics and increase of muscle mass.

The Sertoli cells are stimulated by FSH and testosterone from the Leydig cells. Sertoli cells convert testosterone into estradiol, which inhibits the Leydig cells. Furthermore the Sertoli cells produce nutrients and growth factors for the maturation of the germ cells. Sertoli cells also synthesise inhibin, which has a negative feedback action on FSH secretion.

See also the section on male reproduction in the gynaecology chapter.

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FSH in males supports