Pacemakers of the upper divisions of the digestive tract.

Pacemaker cells of the upper portion of the digestive tract were studied by electromyography of various parts of the stomach and duodenum. Pacemaker cells of the stomach were located mainly at the interface between the lesser curvature and cardia and in the proximal part of the antrum and were characterized by high spontaneous slow-wave and spike activities. Antroduodenal coordination contributes to sequential motor activity of the stomach and duodenum. Pacemaker cells were characterized by a specific shape and a lesser number of myofibrils.