Peritoneal relations of the pancreas

• The pancreas is retro-peritoneal
  
  
• The tail lies in the spleno-renal ligament

Pancreatic duct system :

• The main pancreatic duct (of Wirsung) runs most of the length, to join the common bile duct to form the ampulla of vater
  
  
• It pierces the postero medial wall of the descending part of the duodenum, to open at the summit of the major duodenal papilla.
  
  
• Each of the ducts has a sphincter, and the ampulla of vater is guarded by the sphincter of Oddi. Sometimes the pancreatic and bile ducts open into duodenum separately.
  
  
• There may be an accessory duct(s).

• Fixed by peritoneal relations
• Duct system

Arterial:

Mainly from

•  Superior pancreaticcoduodenal - branch of gastroduodenal

•  Inferior pancreaticoduodenal - branch of superior mesenteric.

These vessels anastomose.

Other sources include:

•  Supraduodenal artery from hepatic artery.

•  Right gastric artery

•  Right gastroepiploic

•  Gastroduodenal

These vessels also anastomose.

Veins:

In general, these follow the arteries and drain into the portal venous system.

Most drain into superior mesenteric, but some may enter the portal vein directly.

One of the anterior veins – the prepyloric vein (of Mayo) ascends anterior to the pylorus and drains into the right gastric vein. This vein consistently runs over the gastroduodenal junction and is an important guidepost to surgeons.

• Posterior and anterior vessels anastome :
  
  
• Follow arteries to the following nodes:
  
  (+) Pancreaticduodenal
  
  (+) Gastroduodenal
  
  (+) Coeliac nodes
  
  
• The posterior ones go Superior mesenteric nodes.

• Parasympathetic and sympathetic from both coeliac and superior mesenteric plexus.
• Pain fibres run with the sympathetic nerves