embryology
Last reviewed 01/2018
Absence of testes causes persistence and development of the paramesonephric ducts or Mullerian ducts. The most cranial part develops into the fallopian tube whilst the more caudal part fuses with that of the opposite side to form the uterine canal and thus, in time, the corpus and cervix of the uterus.
The vagina has a dual origin. The upper part is derived from downward growth of the fused paramesonephric duct; the lower part, from upgrowth of the sinovaginal bulbs, paired evaginations from the urogenital sinus. The hollow vagina is formed by cavitation within these two components.
The hymen is the thin tissue plate which separates the lumen of the vagina from the urogenital sinus.