The Anatomy of the Gallbladder and Pancreas - dummies

The Anatomy of the Gallbladder and Pancreas

By David Terfera, Shereen Jegtvig

As part of the digestive system, the gallbladder and pancreas help you break down food. The gallbladder is a pouch-shaped organ that stores bile produced by the liver. After you eat a meal, a substance called cholecystokinin is secreted by cells in the walls of the duodendum. Cholecystokinin simulates the gallbladder to release the stored bile into the small intestine, where it emulsifies large globules of fats so they’re easier to digest. The gallbladder lies in the gallbladder fossa, which is on the visceral surface of the liver. It’s surrounded by peritoneum that connects it to the liver. It has three parts: the wide fundus (which lies at the midclavicular line at the inferior border of the liver), the body, and the tapered neck that joins the cystic duct.


Nerve supply is brought by the celiac plexus, the vagus nerve, and the right phrenic nerve. Blood is brought to the gallbladder by the cystic artery, which commonly branches from the right hepatic artery. The gallbladder is drained by the cystic veins into the hepatic portal vein and small veins that drain directly into liver sinusoids. Lymph is drained by the cystic lymph node and the hepatic lymph nodes, which drain into the celiac lymph nodes.

The pancreas is a multifunctional organ. It synthesizes enzymes that break down carbohydrates, proteins, and fats and secretes them into the duodenum. It also produces bicarbonates that neutralize the acid that passes from the stomach into the duodenum. The pancreas also produces insulin, a hormone that stimulates cells to take up glucose (blood sugar) from the blood. It lies behind the peritoneum and runs transversely along the posterior wall behind the stomach (between the duodenum of the small intestine and the spleen). It’s divided into four parts:

  • The head is located near the duodenum. It has an uncinate process that projects inferiorly and medially to the left.

  • The neck is the short section that connects to the body.

  • The body continues from the neck to the tail.

  • The tail lies near the hilum of the spleen .

The main pancreatic duct starts at the tail and runs to the head. From there it moves inferiorly and meets the bile duct of the liver to form the hepatopancreatic ampulla. The main pancreatic duct has a sphincter to prevent backflow of bile into the pancreas. The accessory pancreatic duct drains the uncinate process and opens up into the duodenum via the minor duodenal papilla.

Innervation of the pancreas comes from the celiac and superior mesenteric plexuses. Blood is brought to the pancreas by the superior pancreaticoduodenal arteries, branches of the gastroduodenal artery, the inferior pancreaticoduodenal arteries, branches of the superior mesenteric artery, and branches of the splenic artery. Blood is drained away by tributaries of the splenic, and superior mesenteric veins. Lymph is drained by the pancreaticosplenic nodes and pyloric lymph nodes. These nodes drain into the superior mesenteric lymph nodes or the celiac lymph nodes.

Pancreatitis is an inflammation of the pancreas that begins with pain in the upper abdomen, possibly radiating to the back. A person with pancreatitis is quite sick and may have a fever, a rapid pulse, and possibly nausea that leads to vomiting. Pancreatitis can be diagnosed by blood tests and diagnostic imaging techniques such as CT scans and ultrasound. Patients with pancreatitis usually require hospitalization.