what purpose do sphincters serve in the gastrointestinal tract?
Best Answer: First one is the Upper Oesophageal Sphincter, which allows entry of a food bolus into the oesophagus. Then the Lower Oesophageal Sphincter (also known as cardia, or cardiac sphincter), found at the entrance to the stomach. This stops reflux of food back up the oesophagus. Next is the pyloric sphincter, which allows stomach contents into the duodenum (small intestine) for further digestion. Then the ilio-caecal valve, which isn't a sphincter, but mediates movement of small intestine contents into the large intestine (caecum). There are two sphincters around the anus, the external sphincter and the internal sphincter.