external os External orifice of the uterus English External orifice of the uterus External orifice of the uterus external os External orifice of the uterus External orifice of the uterus External orifice of the uterus External orifice of the uterus External orifice of the uterus external os external orifice of the uterus External orifice of the uterus External orifice of the uterus External orifice of the uterus External orifice of the uterus External orifice of the uterus External orifice of the uterus