There are four theoretical parts of the pancreas that will be reviewed in this article from left to right.

Tail of pancreas

The tail of the pancreas is the most lateral of the four parts. It lies anterior to the left kidney and “kisses the spleen”. It passes between the layers of the splenorenal ligament with the splenic vessels (which can be embedded in the pancreas).

Its surrounding structures include the:

• Left kidney - posteriorly;
• Hilum of the spleen - laterally;
• Left colic flexure - inferiorly;
• Stomach - anteriorly (removed for a better view of the pancreas).

Body of pancreas

The body of the pancreas is located to the left of the superior mesenteric artery and vein. It travels over the aorta and the L1 and L2 vertebrae and continues just above the transpyloric plane posterior to the omental bursa (lesser sac).

The body has two surfaces:

• Posterior surface - no peritoneum, and it contacts the aorta, superior mesenteric artery, splenic vein, celiac plexus, left adrenal gland, left kidney, and left renal vessels;
• Anterior surface - faces the omental bursa (lesser sac) and lies posterior to the stomach.

Neck of pancreas

The neck of the pancreas is situated superiorly to the superior mesenteric vessels and posterior to the pylorus of the stomach. 

Posteriorly the superior mesenteric vein and the splenic vein merge to form the portal vein.

Head of pancreas

The head of the pancreas sits in the curve of the duodenum, to the right of the superior mesenteric vessels, at the level of the L2 and L3 vertebra, and rests on the inferior vena cava, right renal artery, and vein, and left renal vein. It is penetrated posteriorly by the common bile duct and pancreaticoduodenal branches of the gastroduodenal artery.

There is a projection extending from the inferior part of the pancreatic head, known as the uncinate process. It extends posteriorly to the superior mesenteric artery and superior mesenteric vein.