Brunner's glands are seen in -: (A) Jejunum, (B) Upper duodenum, (C) Lower duodenum, (D) Appendix
Answer is B. The presence of mucous duodenal (Brunner’s) glands in the submucosa is indicative of upper duodenum. These submucosal glands are absent in the jejunum, ileum and the entire large intestine.