Corpus: Accessory pancreatic duct

The pancreatic ductus accessorius is one of the two excretory ducts of the pancreas of some domestic mammals.

Embryologically, the pancreas arises from two anlagen that develop differently depending on the species. The pancreatic duct arises from the ventral anlage, while the pancreatic duct is derived from the dorsal anlage.

After both pancreatic anlagen have joined together in the centre, different ratios of the excretory ducts develop in different animal species:

• In dogs and horses, both excretory ducts remain. The ductus pancreaticus accessorius opens on the papilla duodeni minor in the cranial section of the duodenum (in dogs about a finger's length away from the papilla duodeni major and in horses antimesenterically).
• Both ducts remain in the cat. However, the pancreatic duct is extremely small. It opens independently about 10 mm distal to the papilla duodeni major into the pars descendens duodeni.
• In pigs and cattle, one duct obliterates so that only the pancreatic duct opens into the duodenum. In pigs, the duct opens on the papilla duodeni minor, about 200 to 250 mm from the pylorus. In cattle, the ductus pancreaticus accessorius reaches the pars descendens of the duodenum about 300 to 400 mm from the papilla duodeni major.
• In sheep and goats, only the duct of the ventral anlage, the pancreatic duct, remains. A pancreatic duct is missing.

See also: Pancreatic duct

• Nickel, Richard, Schummer, August, Seiferle, Eugen. Lehrbuch der Anatomie der Haustiere, Band II: Organsysteme. Parey Verlag, 2003.