Pancreas

• Pancreas

  • Elongated (about 6 inches long), accessory digestive gland, located horizontally on the posterior abdominal wall at the level of L1 and L2 vertebrae (transpyloric plane)
  • 'J' shaped retroperitoneal organ, located behind the stomach and between the duodenum and spleen
  • Has exocrine and endocrine parts

  
• Parts of pancreas

  • Head
  • Neck
  • Body
  • Tail
• Head of pancreas

  • Expanded part of the gland, surrounded by the C-shaped curve of the duodenum
  • Firmly attaches to the descending (2nd) and horizontal (3rd) parts of the duodenum
  • Lower part of head has a projection - uncinate process

  
• Posterior relations of head and body of pancreas

  Inferior vena cava, right renal artery and vein, left renal vein, bile duct (forms a grove on the posterior surface)

  
• Anterior relations of head and body of pancreas

  Transverse colon

  
• Relations of uncinated process

  • Located posterior to the superior mesenteric artery and vein and anterior to abdominal aorta
  • Located above the horizontal (2nd) part of duodenum

  
• Neck of the pancreas

  • Short constricted part between head and body
  • Located behind the neck are - terminal parts of superior mesenteric and splenic veins and origin of portal vein
  • Pylorus of stomach is located anterior to the neck

  
• Body of pancreas

  • Longest part, forms part of stomach bed
• Anterior relations of body of pancreas

  Lesser sac, stomach
• Posterior relations of body of pancreas

  Abdominal aorta, origin of superior mesenteric artery, left kidney, left renal vessels, splenic vein

  
• Upper border of body of pancreas

  Celiac artery and its 2 branches (hepatic and splenic arteries)

  
• Anterior border of body of pancreas

  Gives attachment to greater omentum and transverse mesocolon

  
• Tail of pancreas


  • Lies anterior to the left kidney, and it is closely related to the spleen
  • The tail is relatively mobile and is located in the splenorenal (leinorenal) ligament with the splenic vessels

  
• Pancreatic ducts

  • Main pancreatic duct
  • Accessory pancreatic duct

  
• Main pancreatic duct

  • Begins in the tail, enters wall of 2nd part of duodenum
  • Joins bile duct to form hepatopancreatic ampulla which opens on major duodenal papilla
  • 3 sphincters - sphincter of the pancreatic duct (around the terminal part of the pancreatic duct), the sphincter of the bile duct (around the termination of the bile duct), and the hepatopancreatic sphincter (of Oddi) - around the hepatopancreatic ampulla

  
• Accessory pancreatic duct


  • Begins in the lower part of head
  • Terminates by opening on minor duodenal papilla in the 2nd part of duodenum

  
• Arterial supply of pancreas

  • Splenic artery
  • Superior pancreaticoduodenal artery
  • Inferior pancreaticoduodenal artery

  
• Venous drainage of pancreas

  • Portal vein
  • Splenic vein
  • Superior mesenteric vein

  
• Nerve supply of pancreas

  • Supplied by vagus (parasympathetic) and splanchnic nerves (sympathetic)
  • The parasympathetic fibers are secretomotor, but pancreatic secretion is primarily mediated by secretin and cholecystokinin hormones formed by the epithelial cells of the duodenum and proximal intestinal mucosa under the stimulus of acid contents from the stomach
• Lymphatic drainage of pancreas

  • Lymphatic vessels follow the blood vessels and end in the pancreaticosplenic and pyloric lymph nodes
  • Efferent vessels from these nodes drain to the superior mesenteric lymph nodes or to the celiac lymph nodes (via the hepatic lymph nodes)

  
• Blockage of Hepatopancreatic Ampulla and Pancreatitis

  • Gallstone passing along the bile duct may lodge in the distal end of the hepatopancreatic ampulla resulting in obstruction of both the biliary and pancreatic duct systems
  • Bile may back up and enter the pancreatic duct, usually resulting in pancreatitis (inflammation of the pancreas)
• Pancreatic Cancer


  • Cancer of the pancreatic head – compresses and obstructs bile duct and/or the hepatopancreatic ampulla
  • Results in retention of bile pigments, enlargement of the gallbladder, and obstructive jaundice
  • Cancer of the neck and body of the pancreas – obstruction of portal vein or inferior vena cava

  
• Accessory Pancreatic Tissue

  
• Rupture of Pancreas