The minor duodenal papilla is contained within the second part of the duodenum. It is situated 2cm proximal to the major duodenal papilla, and thus 5-8cm from the opening of the pylorus. The gastroduodenal artery lies posterior.
The minor duodenal papilla may or may not contain a functioning sphincter and patient duct. When present, the sphincter is known as the sphincter of Helly, and the duct theaccessory pancreatic duct of Santorini. In 10% of people, the minor duodenal papilla is the prime duct for drainage of the pancreas,  although in others it may not be present at all.