Peritonealis

Peritonealis is the Latin adjective meaning “of the peritoneum.” In modern medical usage, the term is typically replaced by peritoneal when describing the peritoneum, its membranes, or related processes. The peritoneum is a serous membrane that lines the abdominal cavity (parietal peritoneum) and invests most abdominal organs (visceral peritoneum). The peritoneal cavity contains a small amount of lubricating fluid and facilitates the smooth movement of viscera.

The peritoneum is formed from mesothelium, a simple squamous epithelium, supported by connective tissue. It forms reflections such as mesenteries, omenta, and ligaments that anchor organs to the posterior abdominal wall and to each other. Several organs are intraperitoneal (completely enveloped by peritoneum, e.g., stomach, liver, ileum), while others are retroperitoneal (only partially covered). The peritoneal cavity includes spaces and pouches such as the hepatorenal recess (Morison’s pouch) and the rectouterine or rectovesical pouch, the latter varying by sex.

Functionally, the peritoneum provides a frictionless surface via peritoneal fluid, acts as a barrier to infection, and supports immune surveillance and fluid exchange. It also forms conduits for vessels, nerves, and lymphatics, enabling communication between the abdominal organs and the systemic circulation.

Clinically, disorders involve peritoneal surfaces, including peritonitis (inflammation), ascites (excess fluid), and peritoneal carcinomatosis in cancer. Peritoneal dialysis uses the peritoneal membrane as a dialysis filter.

Etymology and usage: peritonealis is Latin for “of the peritoneum.” The term appears in anatomical descriptions and historical nomenclature; contemporary English generally uses peritoneal.