CAMRT Radiography Practice Exam

What mechanism allows food to move into the duodenum?

1. Pyloric sphincter

2. Cardiac sphincter

3. Lower esophageal sphincter

4. Ileocecal valve

The correct answer is: Pyloric sphincter

The mechanism that allows food to move into the duodenum is the pyloric sphincter. This muscular valve is located at the junction between the stomach and the duodenum (the first part of the small intestine). The pyloric sphincter regulates the passage of partially digested food, known as chyme, from the stomach into the duodenum. It opens in response to the stomach’s contractions and allows small amounts of chyme to enter the duodenum at a controlled rate. This is crucial because it helps ensure that the duodenum has enough time to process food and mix it with digestive enzymes and bile, promoting effective digestion and nutrient absorption. The other options listed serve different physiological roles in the digestive system: the cardiac sphincter controls what enters the stomach, the lower esophageal sphincter prevents acid reflux into the esophagus, and the ileocecal valve regulates the flow of material from the small intestine into the large intestine. Each of these valves plays a vital role in digestion, but only the pyloric sphincter is responsible for allowing food to enter the duodenum.