Chapter030

Chapter 30
Disorders of Hepatobiliary and
Exocrine Pancreas Function
Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins

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

Liver Structure
(cont.)
• Hepatic cells lie along
the sinusoids and pick
up chemicals from the
blood
• They modify the blood’s
composition

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

Liver Structure
(cont.)
• Many sinusoids come
together to empty into
one vein
• The section of the liver
emptying into one vein
is a lobule

Question
Tell whether the following statement is true or false:
The gall bladder stores bile that has been produced by the
liver.

Answer
True
The liver makes bile and secretes it into the small intestine
via the common bile duct. Excess bile is stored in the
gall bladder, where it also enters the small intestine
through the common bile duct when it is needed.

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

Metabolic Functions of the Liver (cont.)
• Drug and hormone metabolism
– Biotransformation into water-soluble forms
– Detoxification or inactivation
• Bile production

Question
Which of the following substances makes bile more
susceptible to digestive enzymes?
a. Carbohydrate
b. Protein
c. Fat
d. All of the above

Answer
c. Fat
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.

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

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.”

Liver Failure
• Hematologic disorders
– Anemia, thrombocytopenia, coagulation
defects, leukopenia
• Endocrine disorders
– Fluid retention, hypokalemia, disordered
sexual functions
– Which hormones would cause these
endocrine disorders?

Liver Failure (cont.)
• Skin disorders
– Jaundice, red palms, spider nevi
• Hepatorenal syndrome
– Azotemia, increased plasma creatinine,
oliguria
• Hepatic encephalopathy
– Asterixis, confusion, coma, convulsions

Jaundice in a Person with Hepatitis A

Question
What causes jaundice?
a. ↑ bilirubin levels
b. Anemia
c. Thrombocytopenia
d. Leukopenia

Answer
a. ↑ bilirubin levels
Erythrocytes are normally broken down in the spleen at the
end of their lifespan. 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).

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)

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?

Chronic Viral Hepatitis
• Caused by HBV, HCV, and HDV
• Principal cause of chronic liver disease, cirrhosis,
and hepatocellular cancer in the world
• Chief reason for liver transplantation in adults

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

Question
Which of the following is the least virulent strain of
hepatitis?
a. HAV
b. HBV
c. HCV
d. HDV

Answer
a. HAV
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 (like contaminated
food or poor hygiene) and does not typically have a
chronic stage (it does not cause permanent liver
damage).

Veins Draining into the Hepatic
Portal System
• Portal hypertension
causes pressure in
these veins to
increase
• Varicosities and
shunts develop
• Organs engorge with
blood

Portal Hypertension
<Insert Figure 30-13>

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)

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
jaundice
liver links it
to
gluconuride
conjugated
bilirubin
bile

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

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

The Pancreas Pancreas
Exocrine
pancreas
releases digestive
juices through a
duct
to the
duodenum
Endocrine
pancreas
releases hormones
into the blood

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

Question
Tell whether the following statement is true or false:
The exocrine pancreas produces insulin.

Answer
False
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.

Biliary Reflux
1. Gallbladder contracts
2. Bile is sent down common bile duct
3. Blockage forms in ampulla of Vater: bile cannot enter
duodenum
4. Bile goes up pancreatic duct
5. Bile in pancreas disrupts tissues; digestive enzymes
activated

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

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

Chapter030

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