Transcript الشريحة 1

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Pancreas is a large gland
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Involved in the digestive process but located outside the
GI tract
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Composed of both exocrine and endocrine functions
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15-25 cm in length
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60-100 gram in weight
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 Two
functionally different tissues:
o Endocrine (hormone releasing)
• The smaller component
• consists of islet of langerhans – 4 cell types
• Secrete 4 hormones
• Insulin, glucagon, gastrin & somatostatin
o Exocrine (enzyme secreting)
• The larger component
• secrets 1.5 – 2 L/day, rich in digestive enzymes
• has alkaline pH due to its content of NaHCO3
• Produced by pancreatic acinar cells
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Completes the job of breaking down food using digestive
enzymes of pancreas
o Protein → trypsin, chymotrypsin
o Carbohydrates → amylase
o Fats → lipase, lecithinase
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Secretes hormones that affect the level of sugar in the
blood.
o Insulin, glucagon
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Produces chemicals that neutralize stomach acids that
pass from the stomach into the small intestine
o NaHCO3
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Most of the pancreatic action is under the hormonal control
of secretin and Cholecystokinin
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 The
major disorders of the pancreas are:
o Endocrine pancreas:
• Diabetes Mellitus (DM)
• Islet Cell Tumors
o Exocrine pancreas:
• Acute pancreatitis & chronic pancreatitis
• Pancreatic cancer
• Cystic fibrosis
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 Tumors
of the pancreatic islets are rare in
comparison with tumors of the exocrine
pancreas.
 Islet cell tumors of the pancreas affect
endocrine capability
o If tumor occurs in beta cells → hyperinsulinism
→ low blood sugar
o Alpha cell tumors → ↑ glucagon → DM
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 Inflammation
of the pancreas
 The exocrine pancreas produces a variety of
enzymes, such as proteases, lipases, and
saccharidases.
 These enzymes start auto-digestion of the
pancreas which causes the pain and
complications of pancreatitis.
 About 80% of cases are associated with
cholelithiasis and alcoholism.
 Associated with raised levels of pancreatic
enzymes (amylase and lipase) in blood and urine.
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 Marked
elevation of the serum amylase
during the first 24 hours, followed within 7296 hours by a rising serum lipase.
 Hypocalcemia
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 Carcinoma
of the pancreas refers to
carcinoma of the exocrine pancreas
 Almost always arising from ductal epithelial
cells (adenocarcinoma).
 Presentation often occurs as a result of
metastases rather than as a direct effect of
the primary tumor.
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Tumor
markers, include:
o carcinoembryonic antigen (CEA),
o CA 19-9,
o and CA 125,
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are associated with pancreatic
cancer but are nonspecific and can be
elevated in conditions other than
malignancies
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Cystic fibrosis is an inherited, autosomal recessive
disease that affects nearly all exocrine glands in the
body.
The disease is characterized by:
o chronic obstructive pulmonary disease,
o pancreatic insufficiency,
o and abnormally high sweat electrolytes.
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The disease causes the exocrine glands to become
obstructed by viscous material.
The blockage leads to cellular damage within the tissue.
Pancreatic insufficiency leads to poor digestion and poor
growth pattern with a deficiency of fat-soluble vitamins.
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CF is caused by a mutation in the gene for the protein cystic
fibrosis transmembrane conductance regulator (CFTR).
This gene is required to regulate the components of sweat,
digestive juices, and mucus.
The diagnosis of cystic fibrosis is made by clinical symptoms
and positive sweat chloride test.
People with cystic fibrosis have unusually large amounts of
chloride in their sweat when compared to reference ranges of
healthy individuals.
The sweat is collected on sterile gauze over a period of a few
minutes and later analyzed for the amount of chloride
present.
Genetic analysis can be used to counsel families for gene
carrier status.
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 Detection
of malabsorption
o Fecal fat test
• Distinguish between pancreatic dysfunction and
intestinal malabsorption
o D-xylose absorption test
• A pentose sugar which does not require pancreatic
enzymes for absorption
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 Measuring
exocrine function
o Secretin, chymotrypsin, trypsin, cholecystokinin
 Measuring
endocrine function
o gastrin, insulin, glucose
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 A 38-year-old
man entered the emergency
department with the complaint of severe, mid
abdominal pain of 6 hours' duration.
 The patient had a 15-year history of alcoholism
 He had last been hospitalized for acute
alcoholism 3 months ago, at which time he had
relatively minor abnormalities of liver function.
 On this admission, his blood pressure was 80/40
mm Hg;
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Serum amylase
640 units (3.5-260 units)
Calcium
4.0 mEq/L (4.5-5.5 mEq/L)
Blood urea nitrogen
32 mg/dL (8-25 mg/dL)
White blood cell count
16,500
Hemoglobin
12 g/dL
1. What is the probable disease?
• Acute pancreatitis
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2.
What is the cause for the low serum calcium?
o
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Enzymatic fat necrosis and digestion, which result in free fatty
acids in abdominal adipose tissue. The fatty acids then bind
calcium as they form fatty acid salts.
What is the cause for the increased blood urea nitrogen?
o Shock, resulting in prerenal azotemia
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