Zenker diveiculum occurs at:: (A) Upper esophageal spinchter, (B) Lower esophageal sphincter, (C) Both of the above, (D) None of the above
Answer is A. Diveicula of the esophagus are mainly located above the LES (epiphrenic diveiculum) or the UES (pharyngoesophageal--or Zenker--diveiculum). They are both caused by abnormalities involving the LES or the UES, which result in protrusion of the mucosa and submucosa through the muscular layers