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This chapter begins with a review of gastric emptying into the intestine and the intestine’s role in regulating gastric emptying. It then discusses the intrinsic innervation of the small intestine, consisting of the interstitial cells of Cajal, the myenteric plexus, and the submucosal plexus. How these components regulate local responses, including secretion and activity of longitudinal and circular muscles, is discussed. The extrinsic innervation through the sympathetic and parasympathetic nervous system is described. The pattern of motility including segmentation, peristalsis, migrating motor complex or migrating myoelectric complex, and reverse peristalsis is mentioned. Neuronal control of peristalsis is discussed. Motility of the large intestine is then discussed, beginning with its patterns. The various motility reflexes in the gut are then described, including receptive relaxation, gastric accommodation, enterogastric inhibitory reflex; gastrocolic reflex; ileal brake; gastroileal reflex; the various reflexes between ileum and transverse colon; and rectoanal inhibitory reflex. This chapter ends with a description of the neural control of vomiting.

Publisher Summary This chapter focuses on ion transport in gastric mucosa. The muscosal surface of the stomach has a large number of openings, which are the gastric pits that produce the gastric secretion. The physiology of secretion can be roughly divided into two parts: one concerned with the basic mechanism by which the cells elaborate the secretion and the second with the control mechanisms. Gastric secretion is controlled by both hormonal and reflex mechanisms. The taste or smell of food can cause the stomach to secrete under conditions where the food does not come in contact with the mucosa. Food in contact with the stomach stimulates the liberation of the hormone gastrin from the antrum into the blood stream. The gastrin in the blood reaches the stomach and stimulates the formation of gastric juice. When the pH of the stomach contents reaches about 2, further liberation of gastrin is inhibited, the acid acting as a negative feedback to gastrin secretion. The chapter discusses the anatomy and physiology of the stomach. Active transport of H+ and Cl− is also analyzed in the chapter.