Home > Peritoneum

1 Structure and development

The peritoneum consists of two layers: the outer layer, called the parietal peritoneum, is attached to the wall of the abdominal cavity and the inner layer, the visceral peritoneum, is wrapped around the organs that are located inside the cavity. The potential space between these two layers is the peritoneal cavity; it is filled with a small amount (about 50 ml) of slippery fluid that allows the two layers to slide freely over each other.

Most abdominal organs are attached to the abdominal wall through a mesentery, a part of the peritoneum through which the organ is supplied with blood and lymph vessels and nerves.

As an embryo develops, the various abdominal organs grow into the abdominal cavity from structures in the abdominal wall. In this process they become enveloped in a layer of peritoneum. The growing organs "take their blood vessels with them" from the abdominal wall, and these blood vessels become covered by peritoneum, forming a mesentery.

2 Function

The peritoneum both supports the abdominal organs and serves as a conduit for their blood and lymph vessels and nerves.

3 The peritoneum in human anatomy

Two notable sections of the peritoneum in humans are the omenta, the greater (gastrocolic) omentum and the lesser (gastrohepatic) omentum. They each comprise a double fold of the peritoneum and contain a cavity (omental bursa or lesser peritoneal cavity). The lesser omentum is attached to the lesser curvature of the stomach and the liver. The greater omentum hangs from the greater curve of the stomach and loops down in front of the intestines before curving back upwards to attach to the transverse colon. In effect it is draped in front of the intestines like an apron and may serve as an insulating or protective layer.

The structures in the abdomen are classified as intraperitoneal or extraperitoneal depending on whether they are covered with visceral peritoneum and have a mesentery or not.

3.1 Intraperitoneal structures

• stomach
• jejunum
• ileumIn anatomy of the digestive system, the ileum (not to be confused with the ilium, a pelvic bone), is the final section of the small intestine. It is about 4m long in humans, follows the jejunum and is separated from the cecum by the iliocecal valve (ICV).
• appendixThe word appendix refers to the following things: In publishing, an appendix is a short section at the end of a book, often used for supplementary information. The literary plural is usually appendices''. In human anatomy, appendix is an abbreviation of v
• spleenThe spleen is a ductless, vertebrate gland that is not necessary for life but is closely associated with the circulatory system, where it functions in the destruction of old red blood cells and removal of other debris from the bloodstream, and also in hol
• transverse colon
• sigmoid colonThe sigmoid colon is the part of the large intestine after the descending colon and before the rectum. The name sigmoid means S-shaped (see sigma). The walls of the sigmoid colon are muscular, and contract to increase the pressure inside the colon, causin
• in women:
  • uterusThe uterus or womb is the major female reproductive organ of most mammals, including humans. One end called the cervix, opens into the vagina, and the wider end, called the body of uterus, is connected on both sides with the Fallopian tubes. It comes in a
  • fallopian tubes
  • ovaries