The pancreas is a gland with endocrine and exocrine functions. It's closely applied to the posterior abdominal wall. To see it we'll look at a dissection in which all of the GI tract except the duodenum has been removed. Here's the pancreas. It's described as having a head, a neck, a body and a tail. The head of the pancreas is closely applied to the inner curvature of the duodenum.
The neck, body and tail of the pancreas extend to the left and slightly upward, ending here close to the spleen which we'll see shortly. Behind the pancreas are the body of L1, the inferior vena cava, the aorta and superior mesenteric artery, and the left kidney.
The lower part of the head of the pancreas curls around to the left, forming the uncinate process. The portal vein passes beneath the neck of the pancreas on its way to the liver.
The exocrine secretions of the pancreas empty into the duodenum by way of the pancreatic duct or ducts. Here we've removed part of the head of the pancreas, to show the main pancreatic duct, entering the duodenum. We'll see more of that in a minute.