How are visceral and parietal layers of the peritoneum differentiated?

The visceral and parietal layers of the peritoneum can indeed be differentiated by their nerve supply. The visceral peritoneum closely adheres to the organs within the abdominal cavity and receives its sensory nerve innervation mostly from the autonomic nervous system, meaning it is less sensitive to pain. In contrast, the parietal peritoneum lines the abdominal wall and is innervated by somatic nerves, primarily from the lower thoracic and lumbar regions, which makes it more sensitive to pain, pressure, and temperature.

This distinction in nerve supply is crucial for understanding clinical presentations of abdominal pain. For example, pain originating from visceral structures can often be referred or more diffuse, while pain from parietal structures is typically sharp and well-localized.