Retroperitoneal space

The retroperitoneal space or simply the retroperitoneal space ( retroperitoneum ) are those anatomical structures that behind the peritoneum ( the peritoneum ) are and are not enclosed by the peritoneum. " Retroperitoneal " means " behind the peritoneum ."

A distinction is evolutionarily primary retroperitoneal and secondarily retroperitoneal organs. Primary retroperitoneal organs are those that occur behind the abdominal cavity. These include the kidneys, adrenal glands and ureters. In contrast, the secondary retroperitoneal organs develop in the abdominal cavity: they are initially intraperitoneally, by growth ( compressive and tensile ) are then pressed these organs in the abdominal wall, the shell of which, the visceral peritoneum, parietal with the peritoneum of the abdominal wall grows together. They therefore have no mesentery ( mesentery ) and more are in their mobility compared to the intraperitoneal organs located very limited. Among the secondary retroperitoneal organs in humans include:

• Pancreas (pancreas)
• Duodenum (exception: upper part, pars superior)
• Ascending colon
• Descending colon
• Rectum to the sacral flexure

In the domestic animals, these organs are, intraperitoneally, with the exception of parts of the pancreas, so possess a mesentery.

In addition to the retroperitoneal organs are located in the median plane of the retroperitoneal space, the large axial pathways:

• Abdominal part ( pars abdominalis ) of the aorta
• Inferior vena cava
• Ascending lumbar vein
• Sympathetic trunk
• Cisterna chyli

• Body cavities