Pelvic part of peritoneum

The pelvic part of the peritoneum (also called the pelvic peritoneum) is the portion of the peritoneal membrane that extends into the pelvic cavity, where it lines the inner walls of the pelvis (as parietal peritoneum) and reflects over the pelvic organs (as visceral peritoneum), creating several clinically important pouches and fossae:

• In females, the peritoneum reflects from the bladder onto the uterus, forming the vesicouterine pouch anteriorly, and from the uterus onto the rectum, forming the rectouterine pouch (pouch of Douglas) posteriorly. Lateral extensions include the paravesical fossae and pararectal fossae.

• In males, the peritoneum reflects directly from the bladder onto the rectum, forming the rectovesical pouch.

The pouch of Douglas (in females) and the rectovesical pouch (in males) represent the most caudal (dependent) portions of the peritoneal cavity, making them common sites for fluid accumulation and pathological collections.

Boundaries and communications. The pelvic peritoneum is continuous superiorly with the infracolic compartment of the abdomen, particularly through the left paracolic gutter. Anteriorly, the urachus and obliterated umbilical arteries indent the peritoneum, creating the supravesical fossa and the medial and lateral inguinal fossae. Posterolaterally, the rectouterine (sacrogenital) folds bound the cul-de-sac.

In women, the peritoneal cavity is not completely closed the fimbriated ends of the fallopian tubes open into it, providing a potential route of communication with the exterior. In men, the peritoneal cavity is a completely closed space.