The esophagus sits in front of your spine and behind the trachea (your windpipe). Your esophagus is made up of four different parts, including the upper esophageal sphincter, the lumen, the gastroesophageal junction (GE) and the lower esophageal sphincter.
Located at the opening of the upper esophagus, the upper esophageal sphincter is a ring of muscle that allows food or liquid to pass through it.
Food and liquids that you swallow move to the inside of the esophagus, called the lumen, towards the stomach.
The gastroesophageal (GE) junction is the name of the connection point where the lower part of the esophagus meets the stomach.
Another ring of muscle near the GE junction, the lower esophageal sphincter, allows food from the esophagus into the stomach. When you’re not eating or drinking, it stays closed to keep acid and digestive juices from the stomach out of the esophagus.
The esophagus wall
The esophagus wall consists of four layers: the mucosa, submucosa, muscularis propria and adventitia.
Mucosa. This layer lines the inside of the esophagus and has 3 parts:
- The innermost lining is called the epithelium and is usually made up of squamous cells. Most esophageal cancers start here.
- The thin layer of connective tissue right under the epithelium is called the lamina propria.
- The thin layer of muscle under the lamina propria is called the muscularis mucosa.
Submucosa. Just below the mucosa is a layer of connective tissue called the submucosa that contains blood vessels and nerves.
Muscularis propria. Under the submucosa is a thick layer of muscle called the muscularis propria that helps push food down the esophagus from the throat to the stomach.
Adventitia. Made up of connective tissue, the adventitia is the outermost layer of the esophagus.