Neurophysiologic Mechanisms of Gastric Reservoir Function

The stomach is a hollow organ in which different anatomic parts such as the cardia, the fundus, the gastric body, the antrum, and the pylorus can be distinguished. Functionally, the stomach consists of a proximal part and a distal part, with a sphincter muscle at both ends. The proximal stomach consists of the fundus and part of the gastric corpus, and its main function is to provide a reservoir to the meal. Smooth muscle cells in the proximal stomach do not display electrical oscillatory activity, and the fundus is characterized by a tonic contractile activity. The distal part of the stomach consists of the gastric antrum and the distal half of the gastric corpus, and its main function is to generate contractions that will mix and grind the food and empty the stomach. Smooth muscle cells in the distal stomach are characterized by the presence of rhythmic electrical activity, so-called slow waves, which determine the timing of gastric contractions.