Description: The pelvis is covered internally with a thin, translucent, serous  peritoneal membrane, continuous with that of the abdominal cavity.  It is described as either parietal or visceral, depending on the underlying structures. The vesical peritoneum anteriorly is hardly noticeable unless the bladder is filled, and when it is, it remains an extra-peritoneal organ covered by parietal peritoneum. Thus, the inferior-most portion of the vesicouterine pouch represents the anterior junction of the parietal and visceral parts. As the membrane drapes upward anteriorly over the uterus, round ligaments, and uterine tubes, it invests these organs with visceral peritoneum. Posteriorly, these organs and their ligamentous structures continue to be covered by visceral peritoneum as it drapes abruptly medially and continues downward to the uterine cervix. There,  it becomes parietal p., covering the sacrouterine ligaments which form as a condensation of endopelvic fascia posterolaterally to the cervix, and between them. As it reaches the rectum, the now visceral p. is reflected  upward and circumferentially, covering the upper half of the rectum and sigmoid colon, and forming their respective  mesentaries posterolaterally. The 'broad ligament', actually a mesentery adjacent to the uterus laterally on either side, is comprised of anterior and posterior parietal peritoneum, with vessels between. Only the ovaries remain without peritoneum. The small mesentery for the uterine tube is called the mesosalpinx, and that for the ovary, the mesoovarium. During pregnancy, the peritoneal sac is greatly distorted as the body and fundus grow and distend upward, carrying the adnexa and adjacent structures with them.