Which structures are retroperitoneal

Extraperitoneal structures are outside the peritoneal cavity. They have been lying outside the peritoneal cavity from the very beginning of the embryological development. They are embedded in connective tissue and are therefore immobile. The locations of retroperitoneal structures on a cross-section. The vertebrae, aorta and inferior vena cava IVC , and kidneys lie posterior to the peritoneum: they lie retroperitoneally.

Extraperitoneal structures lie outside the peritoneal cavity. Moreover, as they lie outside the peritoneal cavity, one does not see them when one opens the peritoneal cavity. Which organs lie extraperitoneal? The kidneys, and the large vessels - the aorta and the inferior vena cava- are the main primary retroperitoneal organs. In the left image, the dashed blue line indicates the peritoneum. The term mesentery is often used to refer to a double layer of visceral peritoneum.

There are generally blood vessels, nerves, and other structures between these layers. The space between the two layers is technically outside of the peritoneal sac, and thus not in the peritoneal cavity. There are two main regions of the peritoneum, connected by the epiploic foramen also known as the omental foramen or foramen of Winslow. The first is the greater sac or general cavity of the abdomen. The second is the lesser sac or omental bursa.

The lesser sac is divided into two omenta: the gastrohepatic and the gastrocolic. The gastrohepatic omentum is attached to the lesser curvature of the stomach and the liver. The gastrocolic omentum hangs from the greater curve of the stomach and loops down in front of the intestines before curving upwards to attach to the transverse colon.

Like a curtain of tissue, it is draped in front of the intestines to insulate and protect them. Substructures of the peritoneum : This is a midsagittal, cross-section drawing of the epiploic foramen, the greater sac or general cavity red , and the lesser sac or omental bursa blue.

The structures in the abdomen are classified as intraperitoneal, retroperitoneal, or infraperitoneal depending on whether they are covered with visceral peritoneum and are attached by mesenteries, such as the mensentery and mesocolon.

Intraperitoneal organs include the stomach, the first five centimeters and the fourth part of the the duodenum, the jejunum, the ileum, the cecum, the appendix, the transverse colon, the sigmoid colon, and the upper third of the rectum. Structures that are not suspended by mesentery in the abdominal cavity and that lie between the parietal peritoneum and abdominal wall are classified as retroperitoneal.

Structures that lie behind the peritoneum are termed "retroperitoneal". Organs that were once suspended within the abdominal cavity by mesentery but migrated posterior to the peritoneum during the course of embryogenesis to become retroperitoneal are considered to be secondarily retroperitoneal organs.

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For more information, see our privacy policy. You can freely give, refuse or withdraw your consent at any time by accessing our cookie settings tool. If you do not consent to the use of these technologies, we will consider that you also object to any cookie storage based on legitimate interest. You can consent to the use of these technologies by clicking "accept". Secondary retroperitoneal structures Characteristics: Visible and accessible after opening the peritoneal cavity and moving the greater omentum aside holds especially for ascending and descending colon; duodenum and pancreas are partially covered by other structures Immobile - fixed to back wall but can easily be detached from back wall again.

Why is it named 'retroperitoneal'? Previous Next. Description: The structures in the abdomen can lie in one of three locations in relation to the peritoneum: intraperitoneal, secondary retroperitoneal or primary retroperitoneal. This page explains the development, adult configuration and characteristics of secondary retroperitoneal organs. Anatomical structures in item: Peritoneum. Requirements for usage You are free to use this item if you follow the requirements of the license: View license.

To be reviewed Information Comment. Uploaded by: opgobee. To be reviewed. Status: to be reviewed. The structures in the abdomen can lie in one of three locations in relation to the peritoneum: intraperitoneal, secondary retroperitoneal or primary retroperitoneal.