Lower esophageal sphincter
This is also called the cardiac sphincter (or gastroesophageal sphincter) and it marks the junction between the esophagus and the stomach. It maintains a constant tone of about 30 mmHg which is higher than the relaxed tone in the midesophagus and only relaxes in front of a peristaltic wave initiated by swallowing which helps to propel swallowed material past this physiological sphincter. This tone may increase prior to sneezing.
The sphincter does not have anatomical features similar to other sphincters in the gastrointestinal tract but the following helps to make it a functional sphincter.
School of Medicine
Creator: Oluwole Ogunranti