The pancreas is located in the posterior wall of the peritoneum of the human body, with a narrow and slightly triangular shape, is a soft gray-red gland, 12-15 cm long, 3-9 cm wide, 1.5-3 cm thick, the pancreas of an adult weighs 70-100 grams, the pancreas of a child weighs 20-50 grams, and the pancreas of a newborn baby weighs about 5 grams.

The male pancreas weighs about 70.3 grams on average, and the female pancreas weighs about 62.9 grams, making it the smaller organ in the abdomen.

The pancreas is divided into four parts from right to left: the head of the pancreas, the neck of the pancreas, the body of the pancreas, and the tail of the pancreas. There is no clear boundary between these parts, and they are divided roughly according to their adjacency and appearance. The head of the pancreas and the neck of the pancreas are located on the right side of the midline of the spine, while the body of the pancreas and the tail of the pancreas are located on the left side.

A line is drawn from the superior duodenal curvature to the superior mesenteric vessels, and this line is the dividing line between the head and neck of the pancreas. The tail of the pancreas is covered by the peritoneum on all sides and is slightly reversible, and the junction between reversible and non-reversible is the junction of the body and tail of the pancreas. The neck of the pancreas is the shortest, the tail is the second shortest, the body is longer, and the head is the widest.

The pancreatic duct runs in the pancreatic parenchyma and consists of the main pancreatic duct and the parapancreatic duct. The main pancreatic duct is located in the center of the pancreas and has a diameter of 2 to 3 millimeters, which begins at the tail of the pancreas and runs across the entire length of the pancreas, with ducts converging along the way to drain pancreatic fluid secreted by pancreatic cells into the duodenum through the main pancreatic duct.

The parapancreatic duct drains pancreatic fluid from the ventral side of the head of the pancreas and opens above the duodenal papilla; most people do not have a parapancreatic duct. Usually, the main pancreatic duct reaches the right edge of the head of the pancreas to join the common bile duct and then enters the medial wall of the descending duodenum, opening over the duodenal papilla.