NHA Certified Clinical Medical Assistant (CCMA)Foundational Knowledge and Basic ScienceMedium
A patient reports experiencing frequent heartburn and a sour taste in their mouth, especially after meals. The medical assistant suspects gastroesophageal reflux disease (GERD). Which of the following anatomical structures is most likely malfunctioning in this condition?
- AIleocecal valve
- BPyloric sphincter
- CLower esophageal sphincter
- DUpper esophageal sphincter
Show answer & explanationAnswer & explanation
Correct answer: C. Lower esophageal sphincter
GERD is characterized by the reflux of stomach acid into the esophagus, which occurs due to a weakening or relaxation of the lower esophageal sphincter, allowing acid to flow backward.
Why the other options are wrong
- A. The ileocecal valve separates the small and large intestines and is unrelated to esophageal reflux.
- B. The pyloric sphincter regulates the passage of food from the stomach to the small intestine, not related to reflux into the esophagus.
- D. The upper esophageal sphincter controls the passage of food from the pharynx into the esophagus and prevents air from entering the esophagus, not stomach acid reflux.
Lower Esophageal Sphincter (LES)
A ring of muscle at the junction of the esophagus and stomach that normally prevents stomach acid from refluxing into the esophagus.
- Acts as a barrier to gastric acid.
- Its relaxation or weakness is a primary cause of GERD.
- Located just above the diaphragm.
Memory trick: LES's laxity lets acid leap upwards.