Chapter 29
Disorders of Hepatobiliary and
Exocrine Pancreas Function
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Liver Structure
• Blood from
hepatic portal
vein and hepatic
artery mix in
sinusoids
• The sinusoids
empty into
central veins,
which send the
blood to the
hepatic vein and
inferior vena
cava
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Liver Structure
(cont.)
• Hepatic cells lie
along the
sinusoids and
pick up
chemicals from
the blood
• They modify
the blood’s
composition
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Liver Structure
(cont.)
• At the back end
of each hepatic
cell, bile is
released into a
canaliculus
• The bile is
carried to the
bile duct and
then to the
gallbladder
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Liver Structure
(cont.)
• Many sinusoids
come together
to empty into
one vein
• The section of
the liver
emptying into
one vein is a
lobule
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Question
Tell whether the following statement is true or false.
The gallbladder stores bile that has been produced by the
liver.
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Answer
True
Rationale: The liver makes bile and secretes it into the
small intestine via the common bile duct. Excess bile is
stored in the gallbladder, where it also enters the small
intestine through the common bile duct when it is
needed.
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Metabolic Functions of the Liver
• Carbohydrate, protein, and lipid metabolism
– Sugars  stored as glycogen, converted to
glucose, used to make fats
– Proteins  synthesized from amino acids;
ammonia made into urea
– Fats  oxidized for energy, synthesized,
packaged into lipoproteins
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Metabolic Functions of the Liver (cont.)
• Drug and hormone metabolism
– Biotransformation into water-soluble forms
– Detoxification or inactivation
• Bile production
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Question
Which of the following substances makes bile more
susceptible to digestive enzymes?
a. Carbohydrate
b. Protein
c. Fat
d. All of the above
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Answer
c. Fat
Rationale: Bile (produced in the liver) emulsifies fat
molecules so that they are easier to digest. An emulsion
is a mixture of two immiscible (unblendable)
substances, in this case bile and fat.
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Scenario
Mr. M had a donut for breakfast.
Question:
• Explain how the sugar in the donut left his
small intestine and ended up as fat in his
carotid artery, giving the:
– Anatomical structures
– Chemical processes
– Hormones that controlled them
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Scenario
Ms. B was prescribed an oral medication for her
skin problem. She took it twice a day.
• The day after she started the medication, Ms. B
drank wine with a friend right after taking the
prescribed dosage
Question:
• Ms. B got terribly ill. Why? She said, “I drink
that kind of wine all the time.”
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Liver Failure
• Hematologic disorders
– Anemia, thrombocytopenia, coagulation
defects, leukopenia
• Endocrine disorders
– Fluid retention, hypokalemia, disordered
sexual functions
– Which hormones would cause these
endocrine disorders?
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Liver Failure (cont.)
• Skin disorders
– Jaundice, red palms, spider nevi
• Hepatorenal syndrome
– Azotemia, increased plasma creatinine,
oliguria
• Hepatic encephalopathy
– Asterixis, confusion, coma, convulsions
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Question
What causes jaundice?
a. Increased bilirubin levels
b. Anemia
c. Thrombocytopenia
d. Leukopenia
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Answer
a. Increased bilirubin levels
Rationale: Erythrocytes are normally broken down in the
spleen at the end of their life span. The end product of
RBC metabolism is bilirubin. Bilirubin is sent to the liver
to be metabolized; if the liver is not functioning
properly, the bilirubin accumulates and causes jaundice
(an abnormal yellowing of the skin and mucous
membranes).
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Hepatitis
• Viral hepatitis
• Hepatitis A virus (HAV)
• Hepatitis B virus (HBV)
• Hepatitis B–associated delta virus (HDV)
• Hepatitis C virus (HCV)
• Hepatitis E virus (HEV)
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Discussion
Which hepatitis viruses are most likely to be the
problem in:
• An asymptomatic drug abuser?
• A nursing student who has spent the last two
months volunteering in an orphanage in Mali?
• An infant whose mother has hepatitis?
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Chronic Viral Hepatitis
• Caused by HBV, HCV, and HDV
• Principal worldwide cause of chronic liver
disease, cirrhosis, and hepatocellular cancer
• Chief reason for liver transplantation in adults
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Alcoholic Liver Disease
• Fatty liver (steatosis)
– Liver cells contain fat deposits; liver is enlarged
• Alcoholic hepatitis
– Liver inflammation and liver cell failure
• Cirrhosis
– Scar tissue partially blocks sinusoids and bile
canaliculi
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Question
Which of the following is the least virulent strain of
hepatitis?
a. HAV
b. HBV
c. HCV
d. HDV
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Answer
a. HAV
Rationale: HBV, HCV, and HDV are all virulent strains that
may lead to chronic viral hepatitis. HAV is most
commonly transmitted by the fecal-oral route (e.g.,
contaminated food or poor hygiene) and does not
typically have a chronic stage (it does not cause
permanent liver damage).
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Veins Draining into the Hepatic
Portal System
• Portal
hypertension
causes
pressure in
these veins to
increase
• Varicosities
and shunts
develop
• Organs
engorge with
blood
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Portal Hypertension
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Cholestasis and Intrahepatic Biliary
Disorders
• Bile flow in the liver slows down
• Bile accumulates and forms plugs in the ducts
– Ducts rupture and damage liver cells
• Alkaline phosphatase released into blood
• Liver is unable to continue processing bilirubin
– Increased bile acids in blood and skin
• Pruritus (itching)
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The Fate of Bilirubin
• Hemoglobin from old
red blood cells becomes
bilirubin
• The liver converts
bilirubin into bile
• Why would a man with
liver failure develop
jaundice?
unconjugated
bilirubin in
blood
bilirubinemia liver links it
to
gluconuride
jaundice
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conjugated
bilirubin
bile
Biliary Tract
Gallbladder
Cystic duct
Hepatic
duct
Common bile
duct
Ampulla of Vater
Sphincter of Oddi
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Pancreatic
duct
Disorders of the Gallbladder
• Cholelithiasis (gallstones)
– Cholesterol, calcium salts, or mixed
• Acute and chronic cholecystitis
– Inflammation caused by irritation due
to concentrated bile
• Choledocholithiasis
– Stones in the common bile duct
• Cholangitis
– Inflammation of the common bile duct
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Bile in the Intestines
• Emulsifies fats so they can be digested
• Passes on to the large intestine
– Bacteria convert it to urobilinogen
º Some is lost in feces
º Most is reabsorbed into the blood
 Returned to the liver to be reused
 Filtered out by the kidneys  urine
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The Pancreas
Pancreas
Exocrine
pancreas
Endocrine
pancreas
releases digestive
juices through a
duct
releases hormones
into the blood
to the
duodenum
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Exocrine Pancreas
• Acini produce:
– Inactive digestive
enzymes
– Trypsin inactivator
– Bicarbonate (antacid)
• These are sent to the
duodenum when it
releases secretin and
cholecystokinin
• In the duodenum, the
digestive enzymes are
activated
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Question
Tell whether the following statement is true or false.
The exocrine pancreas produces insulin.
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Answer
False
Rationale: Beta cells of the endocrine pancreas produce
insulin; the exocrine pancreas produces digestive
enzymes that are secreted into the small intestine
through the common bile duct.
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Biliary Reflux
5. Bile in
pancreas
disrupts
tissues;
digestive
enzymes
activated
1. Gallbladder
contracts
2. Bile is sent
down common
bile duct
3. Blockage forms
in ampulla of Vater:
bile cannot enter
duodenum
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4. Bile
goes up
pancreatic
duct
Autodigestion of the Pancreas
• Activated enzymes begin to digest the pancreas cells
– Severe pain results
– Inflammation produces large volumes of serous
exudate  hypovolemia
• Enzymes (amylase, lipase) appear in the blood
• Areas of dead cells undergo fat necrosis
– Calcium from the blood deposits in them
º Hypocalcemia
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Chronic Pancreatitis and Pancreatic Cancer
• Have signs and symptoms similar to acute pancreatitis
• Often have:
– Digestive problems because of inability to deliver
enzymes to the duodenum
– Glucose control problems because of damage to
islets of Langerhans
– Signs of biliary obstruction because of underlying
bile tract disorders or duct compression by tumors
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