chapter 30 disorders of hepatobiliary and exocrine pancreas function
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Essentials of Pathophysiology. Chapter 30 Disorders of Hepatobiliary and Exocrine Pancreas Function. The liver does not play a role in glucose homeostasis. Jaundice results from an abnormally high accumulation of bile in the blood. - PowerPoint PPT PresentationTRANSCRIPT
CHAPTER 30DISORDERS OF HEPATOBILIARY AND EXOCRINE PANCREAS FUNCTION
Essentials of Pathophysiology
PRE LECTURE QUIZ TRUE/FALSE
The liver does not play a role in glucose homeostasis. Jaundice results from an abnormally high
accumulation of bile in the blood. Hepatitis, inflammation of the liver, is of bacterial
origin. Cholelithiasis, or gallstones, is caused by precipitation
of substances contained in bile, mainly cholesterol and bilirubin.
Chronic pancreatitis is a severe, life-threatening disorder associated with the escape of activated pancreatic enzymes into the pancreas and surrounding tissues.
F
F
FT
F
PRE LECTURE QUIZ The __________ cells are capable of removing
and phagocytizing old and defective blood cells, bacteria, and other foreign material from the portal blood as it flows through the sinusoid.
One of the metabolic functions of the liver is the conversion of ammonia, which is produced by deamination of amino acids, into __________.
Pruritus is the most common presenting symptom in persons with cholestasis, probably related to increased bile __________ in the blood.
Hepatitis __________ is the most common cause of chronic hepatitis, cirrhosis, and hepatocellular cancer in the world.
__________ represents the end stage of chronic liver disease in which much of the functional liver tissue has been replaced by fibrous tissue.
C
Cirrhosis
Kupffer
salts
urea
SYSTEM
SYSTEM INTERACTION
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 STRUCTUR E(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 gallbladder stores bile that has been produced by the liver.
ANSWER
TrueRationale: 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.
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 does bile make more susceptible to digestive enzymes?
a. Carbohydrateb. Proteinc. Fatd. All of the above
ANSWER
c. FatRationale: 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 as the liver fails the spleen
takes over some of the function of the liver Anemia- due to splenomegaly
Thrombocytopenia- due to splenomegaly
coagulation defects- leukopenia due to splenomegaly As your spleen grows larger, it begins to filter
normal red blood cells as well as abnormal ones, reducing the number of healthy cells in your bloodstream. It also traps too many platelets. Eventually, excess blood cells and platelets can clog your spleen, interfering with its normal functioning.
LIVER FAILURE Endocrine disorders
Fluid retention, hypokalemia, Lack of metabolism of aldosterone, too much remains in the system
disordered sexual functions Which hormones would cause these
endocrine disorders? Failure of Cholesterol/Steroid formation
LIVER FAILURE (CONT.) Skin disorders
Jaundice, red palms, spider nevi Hepatorenal syndrome-
Deteriorating liver function is believed to cause changes in the circulation altering blood flow in the kidneys. The renal failure of HRS is a consequence of these changes in blood flow
Azotemia, increased plasma creatinine, oliguria- decreased production of urine
Hepatic encephalopathy- caused by accumulation in the bloodstream of toxic substances that are normally removed by the liver Asterixis, confusion, coma, convulsions Asterixis : An uncontrollable flapping of the hands that
becomes noticeable when patients stretch out their arms, palms out, as if stopping traffic.
JAUNDICE IN A PERSON WITH HEPATITIS A
QUESTION
What causes jaundice?a. Increased bilirubin levelsb. Anemiac. Thrombocytopeniad. Leukopenia
ANSWER
a. Increased bilirubin levelsRationale: 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).
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?
C
E
B
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
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
ALCOHOLIC LIVER
ALCOHOLIC LIVER
LIVER CANCER
QUESTION
Which of the following is the least virulent strain of hepatitis?
a. HAVb. HBVc. HCVd. HDV
ANSWER
a. HAVRationale: 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).
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
PORTAL HYPERTENSION
EFFECTS OF PORTAL HYPERTENSION
Ascites &Caput
medusae
Hemorrhoids
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
BILIARY TRACT
Hepatic duct
Pancreatic duct
Gallbladder
Cystic duct
Common bile duct
Ampulla of Vater
Sphincter of Oddi
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 fecesº 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
FalseRationale: 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
5. Bile in pancreas disrupts tissues; digestive enzymes activated
4. Bile goes up pancreatic duct
1. Gallbladder contracts2. Bile is sent down common bile duct
3. Blockage forms in ampulla of Vater: bile cannot enter duodenum
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 themº 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