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69 Cards in this Set
- Front
- Back
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What is the Pancreas drained by?
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A major and minor pancreatic duct
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Where does the Pancreatic duct drain into the duodenum?
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At the Ampulla of Vater
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What else drains into the duodenum at the Ampulla of Vater?
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The common bile duct
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What 2 types of cells can be found in pancreatic parenchymal tissue?
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-Exocrine cells
-Endocrine cells |
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What are the exocrine cells called?
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Acinar cells
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What do the Acinar cells do?
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Secrete pancreatic enzymes into the pancreatic duct
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What are the endocrine cells called?
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Islets of Langerhans cells
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What do the Langerhans cells do?
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Secrete hormones into blood vessels
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What are we focusing in on?
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The exocrine acinar cells that secrete pancreatic enzymes into the pancreatic duct.
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What is the function of the pancreatic enzymes secreted by the acinar cells?
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Digestion of food in the duodenum
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What are 3 mechanisms by which the body prevents autodigestion by the highly degradative pancreatic enzymes?
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-Enzymes secreted as inactive pro-enzymes (ie, Trypsinogen)
-Enzymes are secreted into little membrane bound vacuoles -Enzyme inhibitors are secreted along w/ the enzymes |
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When is Trypsinogen activated?
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When it meets the enzyme Enteropeptidase in the gut lumen
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What condition results when the protective mechanisms preventing autodigestion go awry?
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Pancreatitis
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So what are the 2 main exocrine secretions of the Pancreas?
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-Digestive enzymes
-Bicarbonate |
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What are the digestive enzymes that the pancreas secretes?
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Proteases - Trypsin and Chymotrypsin
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And what is the manner in which the proteases are synthesized and packaged by the pancreas?
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As inactive proenzymes in secretory vesicles
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What do the secretory vesicles contain other than inactive Chymotrypsinogen or Trypsinogen?
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Trypsin inhibitor - to prevent the activation of trypsinogen into trypsin.
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And what activates Trypsinogen once it is released into the lumen of the small intestine?
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Enteropeptidase
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What 2 other digestive enzymes are secreted by the pancrease in addition to proteases?
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-Lipase
-Amylase |
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What reaction does Lipase catalyze?
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Digestion of Triglyceride into 2-monoglyceride and 2 FFA's
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What else must be present in the intestinal lumen for Lipase to be able to digest triglyceride?
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Bile salts
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What is the function of Amylase?
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Hydrolysis of Starch to Maltose
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In addition to being digestive enzymes, what do we use Lipase and Amylase levels in serum for?
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Detecting Pancreatitis states - their levels would be elevated.
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What are 4 congenital anomalies that can be seen in the pancreas?
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1. Agenesis
2. Pancreas divisum 3. Annular pancreas 4. Ectopic pancreas |
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When the pancreas fails to form (agenesis) what else is usually seen?
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Widespread severe malformations that prevent the baby from living very long.
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Which congenital anomaly is most common?
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Pancreas divisum
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What is Pancreas divisum
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Failure of the main pancreatic duct to form
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To what condition does Pancreas divisum predispose patients? Why?
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Chronic pancreatitis - because the pancreatic juices must all flow through the smaller minor pancreatic duct.
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What is annular pancreas?
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A ring of pancreatic tissue encircling the 2nd portion of the duodenum
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What can annular pancreas result in?
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Obstruction of the duodenum
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What are pancreatic rests?
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Ectopic pancreatic tissue that is normal in appearance
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Why are ectopic pancreatic rests pathologic?
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Because they can cause pain from local inflammation, or mucosal bleeding
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In Pancreatic divisum, why are digestive enzymes released into the pancreas?
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Because the main pancreatic duct tries to empty thru the minor pancreatic duct which is like trying to empty a firehose thru a garden hose
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What does the chronic pancreatitis that occurs in Pancreatic divisum actually consist of?
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Several bouts of acute pancreatitis
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How does the pancreas normally develop?
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By the outpouching of a dorsal bud and ventral bud, which then fuse together
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What congenital anomaly can result from abnormal fusion of the dorsal and ventral primordia of the pancreas?
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Anular pancreas - a ring around the duodenum which can obstruct it partially or fully.
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What are signs of duodenal obstruction in a neonate?
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-Projectile vomiting
-Mass in the abdomen |
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What are the 2 main categories of Pancreatitis, and which is reversible/irreversible?
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Acute - reversible
Chronic - nonreversible |
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What is acute pancreatitis?
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Inflammation of the pancreas
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What can the inflammation in acute pancreatitis range from?
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-Edema/fat-necrosis
to -Parenchymal-necrosis/severe hemorrhage |
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How common is acute pancreatitis in the US?
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Fairly common - the incidence is 10-20/100,000
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What are the 2 major causes of 80% of cases of acute pancreatitis in the US?
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Alcoholism (65%)
Biliary tract disease - Gallstones (35%) |
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What are 4 categories of etiologic factors in Acute Pancreatitis?
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-Metabolic (alcoholism/drugs)
-Mechanical (gallstones) -Vascular -Infectious |
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How can gallstones, which come from the bile duct, obstruct the pancreatic duct?
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Because they both dump into the ampulla of vater and gallstones can actually pass retrograde back into the pancreatic duct.
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What size of gallstones are more likely to migrate thru the biliary tract?
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Small more than large
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What is Saponification?
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Soapy change - a morphologic change that can be seen in acute pancreatitis
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What causes Saponification?
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Fat necrosis due to the release of lipase with subsequent release of anions which bind Calcium
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What are 3 pathogenic mechanisms of acute pancreatitis?
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1. Duct obstruction
2. Acinar cell injury 3. Defective intracellular enzyme transport |
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What can all 3 mechanisms lead to?
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Acinar cell injury and activation of enzymes
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What are 4 lesions that activated enzymes can lead to in the pancreas?
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-Interstitial inflammation/edema
-Proteolysis (proteases) -Fat necrosis (lipase) -Hemorrhage (elastase) |
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And what is the sum result of the lesions caused by activated pancreatic enzymes due to acinar cell injury?
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Acute pancreatitis
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What type of genetic alterations can lead to acute pancreatitis?
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Mutations in the genes encoding the Trypsin inhibitor proteins
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What are the 2 genetic mutations that can be associated with acute pancreatitis?
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-PRSS1
-Spink1 |
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What is PRSS1?
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The gene that encodes for cationic Trypsinogen
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What is the result of PRSS1 mutation?
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Trypsinogen/Trypsin resistant to inactivation; abnormally active trypsin activates other digestive proenzymes
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What is the genetic inheritance pattern of PRSS1?
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Autosomal dominant
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When will PRSS1-induced acute pancreatitis present clinically?
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At childhood
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What does the SPINK1 gene encode for?
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Pancreatic secretory Trypsin inhibitor
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What type of mutations of Spink1 lead to activation of Trypsin and thus pancreatitis?
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Homozygous mutations.
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What is the main clinical feature seen in acute pancreatitis?
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Acute abdomen - abdominal pain
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What is important to remember about acute pancreatitis?
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It is a MAJOR MEDICAL EMERGENCY
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What sort of pain is seen in acute pancreatitis?
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-Constant and intense
-Often referred to the upper back |
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What are 6 potential consequences of acute pancreatitis?
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-Hemolysis
-ARDS -DIC -Diffuse fat necrosis -Acute renal failure -Fluid sequestration, periph. vascular collapse, shock |
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What are 3 lab findings in acute pancreatitis?
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-Elevated Amylase
-Then Lipase -Increased WBCs |
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How is acute pancreatitis managed clinically?
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By resting the pancreas by totally restricting foods/fluids and giving supportive therapy.
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What are 2 complications that can arise as a result of acute pancreatitis?
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-Pancreatic abscess
-Pseudocysts |
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What do Pseudocysts have the potential for?
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Infection
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What is the outcome of most cases of acute pancreatitis?
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Full recovery
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What % of acute pancreatitis cases can result in death?
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As many as 5%
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