Steroid hormone action, male reproductive

III. Male Reproductive Tract Differentiation and the Molecular Biology of Steroid Hormone Action... 

Of the numerous hormones that regulate body function, two steroid hormones are extremely important estradiol, a female sex hormone and testosterone, a male sex hormone. Present in the body in insignificant amounts, they regulate sexual differentiation and reproduction as well as affect the performance of many other physiological systems. Despite the great similarity in chemical structure, they are very different in terms of physiological action. 

Group 1 direct effects on female and male reproductive tract due to gonadal steroid activity (direct hormone action). 

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