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Pancreas - Anatomy & Physiology (view source)
Revision as of 15:28, 21 July 2008
, 15:28, 21 July 2008→Histology
[[Image:Islet and acini.jpg|thumb|right|150px|Acini and islet of Langerhans - © RVC 2008]]
[[Image:Islet and acini.jpg|thumb|right|150px|Acini and islet of Langerhans - © RVC 2008]]
*Consists of acini, which resemble bunches of grapes.
*Consists of acini, which resemble bunches of grapes.
*Each acinus consists of a single layer of epithelial cells surrounding a lumen.
*Each acinus consists of a single layer of 40 - 50 pyramidal epithelial cells surrounding a lumen.
*The epithelial cells produce the secretion (pancreatic juice) containing enzymes, ions and water.
*The epithelial cells produce the secretion (pancreatic juice) containing enzymes, ions and water.
*The secretion drains into a duct called the intercalated duct.
**Cells become wider during active secretion.
**Intercalated ducts converge to make ducts of increasing diameter, which eventually form either the pancreatic or accessory duct.
*The base of the acinar cells are strongly basophilic owing to the presence of endoplasmic reticulum where there is a high concentraion of RNA. This part of the cell therefore stains darker with haematoxylin and eosin.
*The apex of the cells is abundant with secretory granules containing the zymogen precursors of the pancreatic enzymes.
**The number of secretory granules increases after fasting and decreases after a meal.
*The lumen of the acini drain into the intercalated duct.
**Intercalated ducts converge to make larger interlobular ducts, which in turn converge to make interlobar ducts.
***Interlobar ducts are found in the connective tissue septa between lobules.
***Interlobar ducts join to form either the pancreatic or the accessory duct.
**These ducts drain into the duodenum.
**These ducts drain into the duodenum.
**In some cases the pancreatic duct unites with the bile duct, and bile and pancreatic juice enter the duodenum together.
**In some cases the pancreatic duct unites with the bile duct, and bile and pancreatic juice enter the duodenum together.
===Endocrine===
===Endocrine===
*Islets of Langerhans are embedded in the exocrine tissue.
==Species Differences==
==Species Differences==