Goljan Pancreatic disorders Flashcards
What are embryologic abnormalities of the pancreas?
annular pancreas;
aberrant pancreatic tissue (heterotopic rest, choristoma)
How does annular pancreas lead to a GI disorder?
dorsal and ventral buds form ring around duodenum => small bowel destruction
Where are the most common locations for aberrant pancreatic tissue?
wall of stomach;
duodenum; jejunum;
Meckel diverticulum
What do the major pancreatic duct and CBD share?
confluent in terminal part and empty into duodenum via ampulla of Vater
How does the major pancreatic duct lead to the pathogenesis of acute pancreatitis?
stone obstruct terminal part of CBD=>
increased back pressure refluxes bile into major pancreatic duct=>
bile activates proenzymes causing acute pancreatitis
Major causes of acute pancreatitis?
alcohol abuse and gallstones
For acute pancreatitis to occur, what must happen?
activation of pancreatic proenzymes causing autodigestion of pancreas
What are the 5 primary mechanisms of activation of proenzymes causing acute pancreatitis?
obstruction of main pancreatic duct / terminal CBD;
injury of acinar cells;
metabolic activation of proenzymes
What can cause obstruction of the main pancreatic duct or terminal CBD leading to acute pancreatitis?
gallstones;
alcohol thickens ductal secretions => increases duct permeability to enzymes
Injury to acinar cells can occur via 3 types: chemical, infectious, mechanical. Name agents from each category
C: thiazides, alcohol, triglyceride;
I: CMV, mumps, coxsackievirus;
M: seat belt trauma (kids), posterior penetration of duodenal ulcer
what are metabolic causes of proenzyme activation?
hypercalcemia;
ischemia;
shock
What is very important in the activation of proenzymes?
activation of trypsin
If proenzymes are activated prematurely, what are the possible damages?
proteases damage acinar cell structure;
lipases and phospholipases produce enzymatic fat necrosis;
elastases damage vessel walls and produce hemorrhage;
activated enzymes circulate in blood
Define 3rd space fluid
sequestered fluid that is unavailable for maintenance of volume in vascular compartment (nonfxnal ECF)
What does 3rd space fluid refer to in acute pancreatitis?
peripancreatic collection of fluid that commonly occurs as pancreas autodigests itself => hypovolemic shock