# Esophagus --- The **esophagus** is part of the [[digestive system|gastrointestinal tract]] that connects the [[mouth]] to the [[stomach]]. However, no actual digestion happens in the esophagus; it's purpose is only to propel the bolus to the stomach. ## Anatomy At the top of the esophagus is the flap-like **epiglottis**, which closes when you swallow in order to block food from entering the [[respiratory tracts|trachea]] and from there potentially entering the lungs. Just below the epiglottis is the [[sphincter|upper esophageal sphincter]]. At the bottom of the esophagus is the [[stomach|lower esophageal sphincter]] or LES, which opens to allow food in and closes to prevent [[stomach|stomach acid]] from splashing back up. The esophagus has two different layers of muscles that help it propel the food downwards. One layer is the *circular muscle* that goes ring-ways, and a *longitudinal muscle* that goes long-ways. ## Function The esophagus' role is to convey the chewed food from the [[mouth]] (the bolus) to the [[stomach]]. It does this by a series of involuntary contractions called [[peristalsis]]. The circular and longitudinal muscles work together to squish the food all the way down to the stomach. There are **esophageal sphincters** at the superior and inferior ends, which are normally closed at rest. ## Problems With the Esophagus - [[achalasia]] - [[esophageal cancer]] - [[esophageal diverticulum]] ___