The peritoneum is a complex, serous membrane lining the lower abdominal cavity. Its function is to provide a lubricating surface against which the viscera may move so that they are not damaged by friction. In the male body, the peritoneum is predominately a closed, sac-like structure, while in the female, the fallopian tubes penetrate the peritoneum. The peritoneum contains the lesser cavity at the upper abdomen, near the |stomach| and trnsverse colon. The duplicating folds of the peritoneum are called omenta (plural of omentum). The great omentum is the largest of these and hangs down from the |stomach| over the |small intestine|. The great omentum is composed of highly vascularized and innervated |fatty tissue|, protecting the lower viscera from |shock| and ~infection~.
