The tongue manipulates food during chewing and forms it into a bolus which is swallowed. The tongue also tastes the food and pushes the bolus to the pharynx. The pharynx is an intersection for both the digestive and respiratory systems. This directs food through the pharynx and into the esophagus . The esophagus is a muscular tube which conducts food from the pharynx to the stomach.
Peristalsis moves the bolus along the esophagus to the stomach.
Salivary amylase remains active as the bolus moves through the esophagus. The stomach is a large, saclike structure located just below the diaphragm on the left side of the abdominal cavity. The stomach has an elastic wall with rugae - folds that can expand to accommodate up to 2 liters of food. The stomach has longitudinal, vertical and diagonal muscles that contract the stomach in churning movements that mix the food. Stomach contents are mixed about every 20 minutes.