parietaalperitoneumi

The parietal peritoneum is the outer layer of the peritoneal cavity and forms the lining of the abdominal and pelvic walls. It consists of a simple squamous epithelium known as mesothelium, which overlies a connective tissue layer rich in blood vessels. This membrane provides a smooth, lubricated surface that permits the abdominal organs to slide against each other during movements and respiration. The parietal peritoneum is continuous with the visceral peritoneum, which covers the surface of the internal organs, forming the peritoneal cavity that contains a small amount of serous fluid.

During embryologic development, the peritoneum originates from mesodermal tissue that splits into a somatic layer, giving rise to the parietal peritoneum, and a visceral layer, giving rise to the visceral peritoneum. Pain arising from the parietal peritoneum is usually sharp and localized because this layer contains somatic afferent nerve fibers that travel along the abdominal muscle fibers. In contrast, the visceral peritoneum is lymphoid and less sensitive.

Clinically, the parietal peritoneum can become inflamed in conditions such as peritonitis or when it is irritated by adhesions, tumors, or penetrating injuries. In these cases, patients may experience moderate to severe pain, abdominal tenderness, and a reflex of guarding. Surgical interventions, imaging, and anti-inflammatory treatments are employed to manage inflammation and preserve the functional integrity of the peritoneal cavity.