biochem 2 chapter 1
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CHAPTER 1 :PANCREAS
DYSFUNCTIONCLINICAL
BIOCHEMISTRY II(SBD 0113)
MISS SUZAILA BT.ARSAD
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ANATOMY OFPANCREAS
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• Pancreas - small organ, approximately six
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• 1-2 millions tiny clusters of
cells of endocrine tissue ~Islet of Langerhans
• Acinar cells – exocrinefunction
– Secrete pancreatic enzymes
into pancreatic duct – synthesize and secrete
digestive juices.
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• Islet cells - endocrine function
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Islet of Langerhans
• Each islet contains (~2500cells) composed of 4 majorcell types:
– α cells – edge,secrete hormonglucagon
– β cells – centre, secrete
hormon insulin – δ cells – between α & β cells -
secrete hormone GHIH
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F cells – between α cellstowards edge, secrete
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Function of pancreas
EXOCRINE
–creates
enzymes
to digest
fats,
protein
and
carbohy
drate.
ENDOCRINE
–for
maintaining
blood
glucose
levels. normal
range : 70
to 150
mg/dL
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Digestive Enzymes
The exocrine pancreas secretes the pancreatic juice consisting of two
components:
– Pancreatic enzyme – secreted by the acinar cells that form
the acini. Acinar cells secrete 3 different types
of enzymes. What are they? very important because they can
almost completely digest food inthe absence of all other digestive
secretion.
– Aqueous alkaline solution rich in sodium bicarbonate (NaHCO3) actively secreted by the duct cells
that line the pancreatic ducts.
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COMMON PANCREATIC DISEASES cute Pancreatitis
– .Blockage of the pancreatic duct by gallstone
– Can circulate to other body organs causing shock.and organ failure
hronic Pancreatitis
– Associated most often with gall bladder disease and alcoholism
– Lead to other problems such as bacterial.infection and type 2 diabetes
ystic Fibrosis
–Disrupts chloride transport at the cellularlevel
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PANCREATIC FUNCTION TEST
Amylase – – one of several pancreatic enzymes
produced by the pancreas to help digestfats, proteins, and carbohydrates.
– secreted through the pancreatic duct into
the duodenum, where it helps break downdietary carbohydrates. – the most common blood test for acute
pancreatitis.
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It increases from 2 to 12 hours after thebeginning of symptoms and peaks at 12 to72 hours.
It may rise to 5 to 10 times the normal leveland will usually return to normal within aweek.
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Amylase
measures the amount of amylase in theblood or urine - usually present in smallquantities.
Eg. When cells in the pancreas injured orpancreatic duct is blocked
amounts of amylase increase into the
bloodstream
increasing concentrations in the bloodand the urine
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• Urine VS blood amylaseconcentration
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• urine creatinine clearance may beordered along with the urineamylase to help evaluate kidney
function since decreased kidneyfunction can result in a slower rateof amylase clearance.
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Lipase• enzyme that, along with bile
from liver
• Chronic pancreatitiscells destroyed lipase
production drops to <10%of the normal levelsteatorrhea (fatty, foul-
smelling stools)•
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• acute pancreatitis
– very high (2-5X than normal
range) – Rapid and sharp rise within
hours after beginning of attack (4-8 hours,peak 24
hour) – Decline after 4 days
• Low lipase level? – Pancreatic tissue
damage/destruction ….egdisease?
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Trypsinogen
• Proteolytic proenzyme
• Elevated level – during attack
of pancreatitis and renalfailure
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• Decreased level – pancreaticinsufficiency, cystic fibrosisand insulin dependant
diabetes
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er es s a may eused to check for
complications of acute
pancreatitis include: • Complete Blood Count
(including white blood cell
count)• Bilirubin, liver function
tests)
• Glucose• Calcium
• C-Reactive Protein (a
measure of inflammation)
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Other tests that may be used to check for chronic pancreatitis include:
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Fecal elastase test – measures the levels of elastase, an
enzyme found in fluids produced bythe pancreas.
– Elastase digests (breaks down)proteins.
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• - Trypsinogen (Immunoreactivetrypsin) - a serum test that, whenlow, also detects pancreatic
sufficiency•
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Secretin stimulation test
• Secretin
– hormone made by the smallintestines.
– stimulates the pancreas to release afluid that neutralizes stomach acidand aids in digestion
– Prodn of bicarbonate/alkalinepancreatic fluid
• The secretin stimulation testmeasures the ability of the
pancreas to respond to secretin.
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• places a tube down the throat, intothe stomach, then into the upperpart of the small intestine.
• Secretin is administered and thecontents of the duodenal secretionsare aspirated (removed with
suction) and analyzed over a periodof about two hours.
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