Structure of the pancrease

  • By: Terri
  • Date: May 24, 2010
  • Time to read: 2 min.

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The pancrease is a mixed exocrine & endocrine gland.

  • lies tranversely in the posterior abdominal wall
  • L1-L2 level
  • Retroperitoneal (outside peritoneal cavity)
  • Divided into
    • head
    • neck
    • body
    • tail

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Important relations

  • Head
    • lies in the C-shaped concavity of the duodenum
    • IVC & bile duct lie behind the head
  • Neck
    • portal vein behind the neck
  • Body
    • aorta, left renal artery and left suprarenal artery are behind the body
  • Tail
    • left kidney is behind the tail
    • related to splenic hilum

Duct system

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  • Main pancreatic duct
    • extends from the tail to the head
    • joins the bile duct (green) to form the hepatopancreatic ampulla
      • also known as ampulla of vater
      • occasionally both ducts open separately
    • opens into the descending part of duodenum
      • at major duodenal papilla
    • Accessory duct when present communicate with the main pancreatic duct
      • opens to minor duodenal papilla

Smooth muscle sphincters control the flow of bile & pancreatic fluid into the duodenum

  • Pancreatic duct sphincter
  • Bile duct sphincter
  • Hepatopancreatic sphincter (of Oddi)

Blood supply

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Review & confirm again next time.

  • From splenic artery
    • branch: coeliac artery
    • branch: Common hepatic artery
  • From gastroduodenal artery
    • branch: superior pancreatico-duodenal artery
  • From superior mesenteric artery
    • branch: inferior pancreatico-duodenal artery

Venous drainage

Veins accompanies the arteries and then drains to

  • Splenic artery
  • Superior mesenteric vein

Both joins the portal vein and enters the liver.

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Exocrine pancreas

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  • arranged as acini
  • intercalated ducts penetrate the acini
  • around the acini are basement membranes
  • Acinar cells have zymogen molecules
    • proteases
    • lipase
    • amylases

Endocrine pancreas

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  • rounded clusters of cells arranged as islets
    • islet of Langerhans
      • islets arranged as cords & clumps
    • over a million islets
    • more abundant in tail region
  • In between islets have capillaries
    • drain hormones into it

Four types of islet cells

1. A (alpha) – most abundant

    • Glucagon: increases bloog glucose by glycogenolysis, lipolysis & gluconeogenesis

2. B (beta)

    • Insulin: reduces blood glucose

3. D (delta)

    • Somatostatin: inhibits release of other islet cell hormones

4. F

    • pancreatic polypeptides: controls gastric secretions
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