2. 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
3. Liver Structure
(cont.)
• Hepatic cells lie
along the sinusoids
and pick up
chemicals from
the blood
• They modify the
blood’s
composition
4. 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
5. Liver Structure
(cont.)
• Many sinusoids
come together to
empty into one
vein
• The section of the
liver emptying into
one vein is a lobule
6. Question
Tell whether the following statement is true or
false.
The gallbladder stores bile that has been
produced by the liver.
7. True Answer
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.
8. 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
9. Metabolic Functions of the Liver (cont.)
• Drug and hormone metabolism
– Biotransformation into water-soluble forms
– Detoxification or inactivation
• Bile production
10. Question
Which of the following substances makes bile
more susceptible to digestive enzymes?
b. Carbohydrate
c. Protein
d. Fat
e. All of the above
11. a. Fat Answer
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.
12. 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
13. 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.”
14. Liver Failure
• Hematologic disorders
– Anemia, thrombocytopenia, coagulation defects,
leukopenia
• Endocrine disorders
– Fluid retention, hypokalemia, disordered sexual
functions
– Which hormones would cause these endocrine
disorders?
17. 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).
18. 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)
19. 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?
20. 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
21. 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
22. Question
Which of the following is the least virulent strain
of hepatitis?
b. HAV
c. HBV
d. HCV
e. HDV
23. a. HAV Answer
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).
24. Veins Draining into the Hepatic
Portal System
• Portal
hypertension
causes pressure
in these veins to
increase
• Varicosities and
shunts develop
• Organs engorge
with blood
26. 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)
27. unconjugated
The Fate of Bilirubin bilirubin in
blood
• Hemoglobin from old red
blood cells becomes
bilirubin bilirubinemia liver links it
• The liver converts to
bilirubin into bile
gluconuride
• Why would a man with jaundice
liver failure develop
jaundice?
conjugated
bilirubin
bile
28. Biliary Tract
Gallbladder
Hepatic
Cystic duct duct
Common bile
duct
Ampulla of Vater
Sphincter of Oddi
Pancreatic
duct
29. 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
30. 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
31. The Pancreas Pancreas
Exocrine Endocrine
pancreas pancreas
releases digestive
juices through a releases hormones
duct into the blood
to the
duodenum
32. 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
33. Question
Tell whether the following statement is true or
false.
The exocrine pancreas produces insulin.
34. False Answer
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.
35. Biliary Reflux
5. Bile in
1. Gallbladder
pancreas
contracts
disrupts
2. Bile is sent tissues;
down common digestive
bile duct enzymes
activated
3. Blockage forms
in ampulla of Vater: 4. Bile
bile cannot enter goes up
duodenum pancreatic
duct
36. 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
37. Chronic Pancreatitis and Pancreatic
•
Cancer to acute pancreatitis
Have signs and symptoms similar
• 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