The pancreas is long and soft, grayish red or reddish, and can be divided into three parts: head, body and tail. The enlarged pancreatic head is located on the right side and surrounded by the duodenum. The end of the pancreatic duct penetrates into the duodenal wall, joins the common bile duct and opens at the duodenal papilla.

The pancreas is divided into exocrine glands and endocrine glands. Exocrine glands consist of acini (glandular cells) and glandular ducts. The acinus secretes pancreatic juice, and the glandular duct is the channel through which pancreatic juice is discharged. Pancreatic juice contains sodium bicarbonate, trypsin, lipase, amylase and so on. Pancreatic juice flows into the pancreatic duct through all levels of catheters. Both pancreatic duct and common bile duct lead to duodenum. Pancreatic juice is discharged into the duodenum through the pancreatic duct.