The anterior and posterior lobes of the pituitary originate from two distinctly different tissues (neural and epithelial) and anatomical regions in the developing embryo.  The anterior lobe originates from the roof of the mouth and the posterior lobe originates from the brain.  The embryonic gonad develops into testes or ovaries, depending upon the chromosomal makeup of the cells of the genital ridge.  The development of the male reproductive tract requires the presence of testicular determining factor (TDF) and the development of the female tract takes place in its absence.  Both the male and the female reproductive tracts originate from a series of tubes.  In the male, the mesonephric tubules and ducts are used to form the excurrent duct system.  In the female, the paramesonephric ducts form the oviducts, uterus, the cervix and the cranial vagina.