Enteric nervous control of motility in the upper gastrointestinal tract indefensive states

The gastrointestinal tract exhibits patterns of motor behavior that are cha racteristic for specific digestive and pathologic states. Activity of the m usculature, mucosal epithelium, and blood vasculature are coordinated to pr oduce these specific patterns. A neural program for each pattern is stored in the memory of a program library in the enteric nervous system (brain-in- the-gut). The programs are identified by their motility component. They are : (1) segmentation motility in the digestive state of the small intestine; (2) migrating motor complex in the interdigestive state of the small intest ine; (3) orthograde power propulsion in the small and large intestine; (4) retrograde power propulsion in the small intestine during emesis; and (5) p hysiologic ileus. Selective secretory behavior is organized by each program in concert with the motility pattern. The motor program for emesis in the upper gastrointestinal tract reflects an adaptive defense mechanism for mai ntaining gut integrity in response to ingested and/or emotionally perceived insults.