Sensory testing of the human gastrointestinal tract

Figure 1 Afferent nerve supply of the gut. True visceral afferents innervate the gut, and most run temporarily together with either the sympathetic or parasympathetic nerves to enter the spinal cord. During inflammation, silent afferents (dashed line) may become activated and contribute to the sensory response. The peritoneum and parietal serous membranes of the lungs and heart have their own parietal nerve supply, which is organized like that of the somatic structures.