First food enters the mouth and passes through the esophagus.
Swallowing movements bring the food from the esophagus into the cardiac sac. The cardiac sac rhythm serves as the storage area. From the storage areas of the cardiac sac, food moves into the gastric mill, which consists of two lateral teeth and a median tooth, that cut and grind the food. From the gastric mill, food is passed into the pyloric region, where the food particles are separated in the socalled pyloric filter apparatus. The stomatogastric nervous system of decapod crusteans controls the movement of these four parts of the foregut.