Pancreas Ampulla of Vater and Extrahepatic Bile Ducts

The pancreas is a soft, lobulated retroperitoneal organ which is both an endocrine and exocrine gland. The exocrine portion produces enzymes (lipases, proteases) which are conveyed to the duodenum by the pancreatic duct and are concerned with digestion. The endocrine portion (including the islets of Langerhans) produces hormones such as insulin and glucagon. The pancreas is subdivided as follows (Figure 3.1):

• Head - that part to the right of the left border of the superior mesenteric vein. It lies within the concavity of the duodenum. The uncinate process, a part of the head, extends from the left posterior to the superior mesenteric vessels.

• Body - lies between the left border of the superior mesenteric vein and the left border of the aorta.

• Tail - lies to the left of the aorta and comes into contact with the hilum of the spleen. Anteriorly the pancreas has a thin covering capsule.

Superior Head Body Tail mesenteric vein

Figure 3.1. Pancreas. Reproduced with permission from Hermanek P, Hutter RVP, Sobin LH, Wagner G, Wittekind Ch (eds.). TNM Atlas: illustrated guide to the TNM/pTNM classification of malignant tumours, 4th edition. Springer-Verlag: Berlin and Heidelberg, 1997.

Superior Head Body Tail mesenteric vein

Figure 3.1. Pancreas. Reproduced with permission from Hermanek P, Hutter RVP, Sobin LH, Wagner G, Wittekind Ch (eds.). TNM Atlas: illustrated guide to the TNM/pTNM classification of malignant tumours, 4th edition. Springer-Verlag: Berlin and Heidelberg, 1997.

The extrahepatic bile ducts consist of the right and left hepatic ducts, common hepatic duct and common bile duct (Figure 3.2). The hepatic ducts emerge from the porta hepatis of the liver and converge to form the common hepatic duct. This descends for 4 cm until it is joined from the right side by the cystic duct when it becomes the common bile duct. This is 8 cm long and descends in the free edge of the lesser omentum while in the distal part of its course it lies in a groove on the posterior surface of the pancreatic head. The main pancreatic duct runs the length of the gland and just before the ducts enter the duodenum they converge. Together they open into the ampulla of Vater, a small flask-shaped dilated channel situated in the duodenal wall. The ampulla then opens into the duodenal lumen by the major duodenal papilla (Figure 3.2). The distal part of both ducts and the ampulla are surrounded by muscle fibres, this being termed the sphincter of Oddi. The extrahepatic bile duct system may be subject to a number of variations in its anatomy between individuals.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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