The pancreas is a very important organ of the body. It has endocrine and exocrine functions. It is well known for its glucose regulation, which is dysfunctional in the disease diabetes mellitus. This is an autoimmune disease that destroys the insulin-producing cells of the pancreas. The pancreas has 4 parts, the head, the neck, the body and the tail.

Rent

It is rod-shaped and is situated by the L1-L2 vertebrae in both the supracolic and infracolic compartments. It lies at an oblique angle running from right to left at an upward angle. The head is surrounded by the duodenum, the upper, descending and horizontal parts. The pancreas lies anterior to the inferior vena cava and posterior to the stomach. Its body passes over the left renal vein, the aorta, the left crus of the diaphragm, the lower pole of the left adrenal gland, and the hilum of the left kidney. The splenic artery can be found just above the upper border of the pancreas, while the splenic vein runs near the posterior border where it joins the inferior mesenteric vein just in front of the renal vein.

Structure

The pancreas is finely lobulated and of a solid consistency. It is composed of 80% exocrine acini with scattered ‘islets of Langerhans’ constituting 2% of the endocrine portion. The other 18% is made up of ducts and vessels. The islets are located mainly in the tail of the pancreas. The pancreatic duct runs from the tail to the head and grows as more tributaries join it. It then joins the bile duct to form the hepatopancreatic ampulla which empties through the major papilla into the proximal duodenum at the junction of the foregut and midgut. The lower part of the head and the uncinate process are drained by the accessory pancreatic duct that drains through the minor papilla, located 2 cm above the major papilla. The hepatopancreatic ampulla is surrounded by sphincter muscle, the ampullary sphincter of Oddi is the mechanism for controlling flow in the ducts. It often has a bottom-located portion that points up and to the left, called the uncinate process.

blood supply

The blood supply of the pancreas is mainly from branches of the splenic artery that supply the neck, body, and tail. Branches include the dorsal pancreatic artery, the inferior, and the greater pancreatic arteries. The head is supplied by the superior and inferior pancreaticoduodenal arteries, which arise from the celiac and mesenteric arteries, respectively. The veins that drain the pancreas drain into the splenic vein, superior and inferior pancreatoduodenal veins. The last two that drain into the mesenteric veins.

lymphatic drainage

In the head of the pancreas, lymphatic drainage follows the pancreaticoduodenal arteries and ultimately drains into the celiac and mesenteric lymph nodes. The body drains into the pancreaticosplenic nodes, eventually terminating in the celiac nodes.

innervation

Branches of the vagus nerve reach the pancreas via the posterior vagal trunk and celiac plexus, which stimulate exocrine function. Sympathetic vasoconstrictor fibers originate at T6-T10 and pass through the celiac plexus.