A 17 year old girl is brought into the casualty with severe abdominal pain and a fever. Laboratory examination is remarkable for an elevated white blood cell count and a pregnancy test is positive. Upon questioning, it is determined that she attempted to terminate her pregnancy by inseing a sharp object into her vagina. The physician determines that the wall of the posterior fornix of the vagina has been penetrated. Into what region did the sharp object penetrate?

The posterior fornix is in contact with the floor of the rectouterine space. The rectouterine space is the lowest pa of the peritoneal cavity in the female pelvis. The patient has introduced bacteria into the peritoneal cavity by the penetration of the sharp object, producing sepsis. The deep perineal pouch is the middle layer of the urogenital diaphragm containing the sphincter urethrae muscle. The vagina passes through this region but the posterior fornix is not related to it. The ischioanal space is below and lateral to the pelvic diaphragm. The vagina does not pass through this space. The rectovesical space is the region in the peritoneal cavity of the male pelvis between the urinary bladder and the rectum. This space does not exist in the female pelvis.