What is the muscular opening between the esophagus and stomach?

What is the muscular opening between the esophagus and stomach?

• A. Cardioesophageal sphincter
• B. Pyloric sphincter
• C. Anal sphincter
• D. Sphincter of Oddi

Answer: (A)

The muscular opening between the esophagus and stomach is the cardioesophageal sphincter, also called the lower esophageal sphincter. This ring of smooth muscle sits at the gastroesophageal junction and stays tonically contracted to prevent gastric reflux. During swallowing it relaxes to let the food bolus enter the stomach. The other options are not correct for this location: the pyloric sphincter sits between the stomach and the duodenum; the anal sphincter is at the end of the GI tract, controlling defecation; the Sphincter of Oddi regulates bile and pancreatic juice entry into the duodenum.

The muscular opening between the esophagus and stomach is the cardioesophageal sphincter, also called the lower esophageal sphincter. This ring of smooth muscle sits at the gastroesophageal junction and stays tonically contracted to prevent gastric reflux. During swallowing it relaxes to let the food bolus enter the stomach.

The other options are not correct for this location: the pyloric sphincter sits between the stomach and the duodenum; the anal sphincter is at the end of the GI tract, controlling defecation; the Sphincter of Oddi regulates bile and pancreatic juice entry into the duodenum.