Where are the kidneys located in relation to the peritoneum?

• A. Intraperitoneal, between the peritoneal layers.
• B. Retroperitoneal, behind the parietal peritoneum.
• C. In the pleural cavity.
• D. Within the liver.

Answer: (B)

The kidneys are located in the retroperitoneal space, meaning they lie behind the parietal peritoneum and against the posterior abdominal wall. They are not enclosed within the peritoneal cavity and are only partially covered by peritoneum on their anterior surface, with the rest in contact with muscles and fascia of the back. This positioning explains why they’re described as retroperitoneal rather than intraperitoneal or intrahepatic.

In contrast, intraperitoneal organs are enclosed by peritoneum and suspended within the abdominal cavity by mesenteries, which isn’t the case for the kidneys. The pleural cavity is part of the thoracic cavity, not the abdomen, and the liver is an intraperitoneal organ in most individuals, not the location of the kidneys.