Lower Esophageal Sphincter

From Anvita Health Wiki

Contents 1 Introduction 2 More General Terms 3 Additional Terms 4 References

Introduction

• Tonic contraction of the LES contributes to prevention of gastroesophageal reflux. The crural portion of the diaphragm contributes to the LES pressure. Thus a hiatal hernia weakens the LES & may predispose to gastroesophageal reflux disease ( GERD). Relaxation of the LES allows food to pass with swallowing. Transient relaxation of the LES (not associated with swallowing) is the most common cause of GERD.

• Foods lowering the LES pressure:

• chocolate

• Pharmaceuticals lowering LES pressure:

• nitrates
• calcium channel blockers
• benzodiazepines
• anticholinergics
• antidepressants
• estrogen & progestin might reduce LES pressure by increasing blood levels of nitric oxide

More General Terms

• gastrointestinal structure
• sphincter

Additional Terms

• diaphragm muscle
• gastroesophageal reflux disease (GERD)
• hiatal (diaphragmatic) hernia
• swallowing (deglutition)

References

1. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
2. Chait M, Clinical Geriatrics 12(4): 39, 2004
3. Prescriber's Letter 15(11): 2008 Hormone Therapy and the Risk for GERD Detail-Document#: [1] (subscription needed) [2]
   - Jacobson BC et al. Postmenopausal hormone use and symptoms of gastroesophageal reflux. Arch Intern Med 2008 Sep 8; 168:1798. PMID: [3]

lower esophageal sphincter (LES)