Anatomy
Summary
The peritoneum is the serous membrane that lines the abdominopelvic cavity and protects the abdominal organs. This membrane includes two layers: the visceral peritoneum (covers the organs) and the parietal peritoneum (covers everything else). Between these layers is the peritoneal cavity, which contains peritoneal fluid that allows the layers to slide against each other. Abdominopelvic organs can be classified as intraperitoneal or extraperitoneal based on their location relative to this cavity.
Intraperitoneal organs reside inside the peritoneal cavity. They are supported in place by the mesentery, a structure made from folded peritoneum. The mesentery also conducts blood vessels, nerves, and lymphatics to and from the intraperitoneal organs. These organs include the stomach, liver, spleen, tail of pancreas, first part of the duodenum, jejunum, ileum, appendix, and transverse and sigmoid colon.
The extraperitoneal space includes the retroperitoneal and subperitoneal spaces. Retroperitoneal organs are covered anteriorly by parietal peritoneum. Extraperitoneal organs include: suprarenal glands, aorta, inferior vena cava, 2nd-4th parts of the duodenum, pancreas (except tail), ureters, kidneys, colon (ascending and descending), esophagus, and rectum. Lastly, the bladder, an extraperitoneal organ, lies in the subperitoneal space when empty, but moves into the preperitoneum as it fills.
Lesson Outline
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FAQs
Intraperitoneal organs are covered by the visceral peritoneum and positioned within the peritoneal cavity. They include the stomach, liver, spleen, tail of pancreas, first part of the duodenum, jejunum, ileum, appendix, and transverse and sigmoid colon. These organs are connected to the abdominal wall by a double layer of peritoneum, known as the mesentery.
The extraperitoneal organs are located in the extraperitoneal space, outside the peritoneal cavity, unlike the intraperitoneal organs. The extraperitoneal organs include the suprarenal glands, aorta, inferior vena cava, 2nd-4th parts of the duodenum, pancreas (except tail), ureters, kidneys, colon (ascending and descending), esophagus, rectum, and bladder.
The peritoneum is a serous membrane made up of two layers: the parietal peritoneum and the visceral peritoneum. The visceral peritoneum envelops the intraperitoneal organs. Between the layers is a potential space called the peritoneal cavity, which contains peritoneal fluid that allows the layers to slide freely against each other.
The mesentery is a double layer of peritoneum that extends from the body wall to the organs. It helps to hold intraperitoneal organs in place within the peritoneal cavity, and also provides a conduit for blood vessels, nerves, and lymphatic vessels to reach the organs.
