Final answer:
The esophagus is the muscular tube that food travels through on its way to the stomach, and peristalsis is the involuntary movement that pushes the food down.
Step-by-step explanation:
The part of the body that food travels through on its way to the stomach is the esophagus. The esophagus is a muscular tube connecting the pharynx to the stomach, approximately 25.4 cm (10 inches) in length in adults. The inner lining of the esophagus consists of a mucous membrane, providing a smooth surface for the passage of food.
During swallowing, food is kept out of the trachea by the epiglottis, which covers the glottis to prevent food from entering the respiratory system. Once the bolus of food is in the esophagus, smooth muscle contractions called peristalsis push the food toward the stomach. This is a unidirectional movement and occurs as an involuntary reflex.