The esophagus is a muscular, hollow tube that connects the throat (pharynx) to the stomach. Its primary function is to transport food and liquids from the mouth to the stomach for digestion
. When you swallow, the upper esophageal sphincter (a circular muscle at the top of the esophagus) relaxes to allow food or liquid to enter. Then, rhythmic muscular contractions called peristalsis push the food down through the esophagus. If the initial wave of peristalsis is insufficient, secondary peristalsis helps move the food along
. At the bottom, the lower esophageal sphincter opens to let the food pass into the stomach and then closes to prevent stomach contents, including acid, from flowing back into the esophagus, protecting it from damage
. In summary, the esophagus serves as a conduit that moves swallowed food and liquids safely from the mouth to the stomach through coordinated muscle contractions and sphincter control, also helping prevent reflux of stomach contents back into the esophagus
