What is the first part of the digestive tract that food passes through?

The mouth is the first part of the digestive tract that food passes through when eating. It serves as the entry point for food intake, where the process of digestion begins. In the mouth, food is mechanically broken down by chewing and mixed with saliva, which contains enzymes that initiate the chemical breakdown of carbohydrates. This initial mixing of food and saliva creates a bolus, which is then swallowed and moves into the pharynx, subsequently traveling down the esophagus to the stomach.

The pharynx acts primarily as a passageway for food and air but is not where digestion begins. The esophagus serves solely as a conduit to transport the bolus from the pharynx to the stomach, while the stomach is a storage and mixing chamber where further digestion occurs. Therefore, understanding the roles of each part of the digestive tract clarifies the reason why the mouth is recognized as the starting point in the digestion process.