production gonadotropins. fsh and lh are synthesized in the pituitary gland in response to gonadotropin-releasing

production gonadotropins fsh lh synthesized gonadotropin releasing hormone gnrh hypothalamus pituitary gonad axis medicine fertilization illustration woman vector secretion structure estradiol produced steroid follicles ovaries major female regulation reproductive cycles estrous menstrual estrogen synthesis ovary brain luteinizing follicle stimulating gland male regulates spermatogenesis testosterone testis