Digestion starts in the mouth where chewing and saliva breaks down food so it is more easily processed by your body. Esophagus: The esophagus is a muscular tube that connects the pharynx (throat) to the stomach. The esophagus contracts as it moves food into the stomach. A âvalveâ called the lower esophageal sphincter (LES) is located just before the opening to the stomach. This valve opens to let food pass into the stomach from the esophagus and it prevents food from moving back up into the esophagus from the stomach.