Female reproductive system fetal development

The female reproductive system is also at risk during fetal development in utero, postnatally during puberty, and during her reproductive lifetime until menopause (cessation of ovulation). The traditional end points of concern are ovulation of a normal ovum, fertilization, uterine status, implantation and prenatal development, parturition, and lactation involving nursing (appropriate quality and quantity of milk) and other maternal behaviors. 

Adversely affect the growth and development of conceptus (lower fetal weight) (in female reproductive system)... 

Reproductive toxicity to 2,3,7,8-TCDD has been demonstrated in animals. "" The effects include pre- and postimplantation losses in females, morphologic and functional changes in male and female reproductive organs, and hormonal imbalance in both sexes. A number of developmental effects have been observed in animals acutely exposed to 2,3,7,8-TCDD by the oral route. Effects observed in offspring of animals include cleft palate, kidney anomalies, immune system damage (thymic atrophy and immunosuppression), impaired development of the reproductive system, decreased growth, and fetal/newborn mortality. 

Two important aspects of early development of the reproductive tract are that the fetal gonad is structurally indifferent in male and female embyros and that the fetal reproductive system can therefore develop as male or female. Thus, the first major step in development of the reproductive system is establishing gonadal sex. Sex of the embryo depends on whether the spermatozoon carries an X or Y chromosome, and sexual differentiation of the indifferent structures in the gonad is necessary to form the male or female reproductive tract. The SRY gene on the Y chromosome is needed for testicular... 

Sexual differentiation of the central nervous system also occurs during fetal development, and it is equally fundamental to reproductive function during adulthood. Adult males exhibit a relatively continuous pattern of gonadotropin secretion from the hypothalamic-pituitary axis and are therefore fertile throughout their reproductive lifetime. In contrast, adult females exhibit a cyclical pattern of gonadotropin secretion and are fertile only during the transient period that follows ovulation during each reproductive cycle. This fundamental difference is due to irreversible... 

Developmentally, the reproductive system of vertebrates has two outcomes, male or female. While it is convenient to envision these two outcomes as dichotomous, the reality is not so simple. As discussed above, genetic males do not always develop into morphological ones, not even in mammals. Changes in the chemical environment in which fetal or larval animals develop are important, as they can disrupt the endogenous endocrine signals, causing alterations in reproductive development. Furthermore, the plasticity... 

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