MS-1390

An 80-year-old woman visits her doctor with complaints of moderate upper abdominal pain that is slightly relieved by eating. Despite taking ibuprofen, she has not experienced any relief. The doctor suspects a duodenal peptic ulcer and schedules an oesophagogastroduodenoscopy (OGD). Based on the location of the ulcer, which organ is derived from the same embryological region of the gut?