What are organs called that invaginate the peritoneum and are covered by it?

Intraperitoneal organs are defined as those that are completely surrounded by the peritoneum, a serous membrane that lines the abdominal cavity and covers the abdominal organs. This configuration means that these organs are suspended within the abdominal cavity and have a greater degree of mobility compared to other classifications. Examples include the stomach, liver, and intestines.

In contrast, organs classified as extraperitoneal lie outside the peritoneal cavity and are not covered by the peritoneum. Subperitoneal organs are located beneath the peritoneum, while retroperitoneal organs are situated behind the peritoneum but are not enveloped by it. These distinctions are critical for understanding organ placement and potential clinical considerations such as fluid accumulation or the spread of infection within the abdominal cavity.