<prompt> Upper one third of vagina is derived from:Sinovaginal bulbMullerian ductWollfian ductGenital ridge  <response>: Uterovaginal canal fused Mullerian or paramesonephric ducts forms upper 13rd vagina, lower 23rd is formed from urogenital sinus. Uterovaginal canal mesoderm comes in contact with the urogenital sinus endoderm. Sinovaginal bulbs are formed by the proliferation of endodermal lining. Solid vaginal plate is derived paly from mesoderm of uterovaginal canal and paly from endoderm of sinovaginal bulbs. Vagina is formed by canalization of vaginal plate. Ref: Snells, Clinical Anatomy, 7th Edition,Page 404; Human Embryology, 7th Edition, Page 283. 