Impacted food bolus common ED complaint
4 areas of narrowing in the esophagus
Upper esophageal sphincter (cricopharyngeus muscle)
Aortic arch
L mainstem bronchus
Lower esophageal sphincter<unk> : mucosal or muscular tissue<unk> 
Upper esophageal sphincter (cricopharyngeus muscle)
Aortic arch
L mainstem bronchus
Lower esophageal sphincter
Schatzki ring
Oropharyngeal dysphagia
Bezoar
CVA
Faget sign
Parkinson's disease
Mallory-Weiss tear
Brain stem tumors