The skin constitutes the metabolically active biological barrier separating the internal milieu of mammalian organism and the external environment. The skin is continuously exposed to hostile environmental factors, therefore the anatomic localization determines its many functions. Both, the central endocrine system and the cutaneous endocrine system control and integrate the functions. All factors controlling the activity of the hypothalamus-pituitary-target organ axis are expressed in the skin.

The development of male reproductive system induced and controlled by hormones produced in the testis differentiation . Androgen insensitivity caused by a mutation of the AR receptor , or the lack of activity of 5a - reductase which convert T to DHT , are the cause of developmental abnormalities and often the cause of male infertility . Similar effects causes no effects of estrogen , resulting from mutations in the cytochrome P450 aromatase gene and a team of resistance to these hormones , caused by mutation of estrogen receptors .