A vesicovaginal fistula is an abnormal opening between the and that allows constant involuntary flow of urine from the into the .

The words that best fit the underlined spaces in the statement would be "bladder", "vagina", "bladder", and "vagina" in which it is arranged in order. In addition, this part of the urinary system of a female allows the passage of urine through the contraction of the vaginal vault.