Chapter 25 - Liver Function (RVSP) Flashcards
Amount of blood that passes into the liver per minute
1500 mL/min
Average weight of the liver
1200-1500 g
Spaces between hepatocytes
Sinusoids
2 blood vessels that supply blood to the liver
- hepatic artery
- portal vein
3 systems of the liver
- hepatocyte system
- biliary system
- reticuloendothelial system (RES)
System of the liver; for metabolic reactions and macromolecular synthesis
Hepatocyte system
System of the liver; for metabolism of bilirubin and bile salts
Biliary system
System of the liver; for excretory function
Biliary system
Structure of the liver involved in excretion
Bile canaliculi
System of the liver for drug metabolism
Hepatocyte system
Drug metabolism function of the liver
Xenobiotic
System of the liver; for immune system and degradation of hemoglobin
Reticuloendothelial system
Cells involved in the reticuloendothelial system
Kuppfer cells
4 functions of the liver
- Synthesis
- Excretory/secretory
- Detoxification
- Storage
Removal of waste products
Excretion
Release of useful substances
Secretion
2 proteins not produced by the liver
- Immunoglobulins
- adult hemoglobin
4 substances synthesized by the liver
- proteins
- carbohydrates
- lipids
- vitamins
2 ways the liver detoxifies toxic substances
- bind and inactivate toxin
- chemically modify and excrete toxin
4 substances stored by the liver
- proteins
- lipids
- amino acids
- glycogen
Principal pigment in bile
Bilirubin
Amount of bile produced per day
3 L/day
Amount of bile excreted per day
1 L/day
2 components of bilirubin
- RBCs (80%)
- proteins (20%)
Divides the liver into two unequal lobes
Falciform ligament
Larger lobe of the liver
Right lobe (6x larger)
Supplies oxygen-rich blood to the liver; 25% of total blood supply to the liver
Hepatic artery
Supplies nutrient-rich blood to the liver; 75% of total blood supply to the liver
Portal vein
Functional units of the liver
Lobules
Responsible for all metabolic and excretory functions of the liver
Lobules
Centrally located vein of the lobule
Central vein
Found at each side of the lobule
Portal triads
3 components of the portal triads
- hepatic artery
- portal vein
- bile duct
2 major cell types of the liver
- hepatocytes
- Kupffer cells
Liver cells responsible for its regenerative properties
Hepatocytes
Active phagocytes in the liver
Kupffer cells
Major heme waste product
Bilirubin
Type of bilirubin bound by albumin
Unconjugated/indirect bilirubin
Solubility of indirect bilirubin to alcohol and water
- soluble to alcohol
- insoluble to water
Protein for transport of unconjugated bilirubin to the endoplasmic reticulum
Ligandin
Enzyme for the conjugation of bilorubin
Uridyldiphosphate glucoronyl transferase (UDPGT)
Solubility of direct bilirubin to alcohol and water
- insoluble to alcohol
- soluble to water
Amount of bilirubin produced per day
200-300 mg
Enzymes responsible for the drug-metabolizing system of the liver
Cytochrome P-450 isoenzymes
Yellow discoloration of the skin, eyes amd mucous membranes
Jaundice/icterus
Most common cause of jaundice
Retention of bilirubin
Jaundice not visible to the naked eye
Overt jaundice
Bilirubin levels when jaundice is visible
3.0 - 5.0 mg/dL
3 classifications of jaundice
- prehepatic/hemolytic hyperbilirubinemia
- hepatic/hepatocellular hyperbilirubinemia
- posthepatic/obstructive hyperbilirubinemia
Jaundice that occurs when the problem happens prior to liver metabolism
Prehepatic jaundice
Another name for prehepatic jaundice
Unconjugated hyperbilirubinemia
Type of anemia that causes prehepatic jaundice
Acute and chronic hemolytic anemia
Jaundice that occurs when the problem resides inside the liver
Hepatic jaundice
3 diesease that cause hepatic jaundice that increases unconjugated bilirubin
- physiologic jaundice of the newborn
- Gilbert’s disease
- Crigler-Najjar syndrome
2 conditions that cause hepatic jaundice that elevates conjugated bilirubin
- Dubin-Johnson
- Rotor syndrome
Most common cause of hepatic jaundice
Gilbert’s syndrome
Type of hepatic jaundice where there is impaired cellular uptake of bilirubin
Gilbert’s syndrome
Type of hepatic jaundice; chronic nonhemolytic unconjugated hyperbilirubinemia; deficiency of UDPGT
Crigler-Najjar syndrome
Type of Crigler-Najjar syndrome; complete absence of UDPGT, no B2 formed, colorless bile
Type I
Type of Crigler-Najjar syndrome; relative deficiency of UDPGT, some B2 formed
Type II
Condition of relative deficiency of UDPGT
Arias syndrome
Conjugated bilirubin bound to albumin
Delta bilirubin
Type of hepatic jaundice caused by a deficiency of the canalicular multidrug resistance/multispecific organic anionic transporter protein (MDR2/cMOAT)
Dubin-Johnson syndrome
Type of hepatic jaundice where the removal of conjugated bilirubin from the liver cell and the excretion into the bile are defective
Dubin-Johnson syndrome
Type of hepatic jaundice that is idiopathic
Rotor syndrome
Appearance of liver in Dubin-Johnson syndrome
With black pigmentation
Appearance of liver in Rotor syndrome
Normal histology
Gallbladder visualization of Dubin-Johnson syndrome
No visualization
Gallbladder visualization of Rotor syndrome
Visualized by oral cholecystogram
Total urine coproporphyrin of Dubin-Johnson syndrome
Normal w/ >80% of isomer 1
Total urine coproporphyrin of Rotor syndrome
High w/ <70% of isomer 1
Enzyme that is deficient in physiologic jaundice of the newborn
Glucoronyl transferase
Movement of bilirubin from the bloodstream to brain tissue
Kernicterus
Enzyme responsible for bilirubin conjugation in infants
Glucoronyl transferase
Jaundice caused by biliary obstructive disease
Posthepatic jaundice
Type of bilirubin increased in posthepatic jaundice
- unconjugated
- conjugated
Type of jaundice where the stool loses its normal pigmentation and becomes clay-colored
Posthepatic jaundice
Condition in which scar tissue replaces normal, healthy liver tissue
Cirrhosis
Most common cause of cirrhosis
Chronic alcoholism
Type of liver cancer that begins in the liver cells
Primary liver cancer
Type of liver cancer that occurs when tumors from other parts of the body spread to the liver
Metastatic cancer
3 cancers that commonly spread to the liver
- breast cancer
- lung cancer
- colon cancer
2 types of liver cancer
- primary liver cancer
- metastatic liver cancer
2 types of liver tumors
- benign tumors
- malignant tumors
2 common benign liver tumors
- Hepatocellular adenoma
- hemangiomas
2 malignant liver tumors
- hepatocellular carcinoma (HCC)
- bile duct carcinoma
Benign liver tumor occuring in females of child-bearing age
Hepatocellular adenoma
Benign liver tumor; masses of blood vessels with no known etiology
Hemangiomas
Most common malignant liver tumor
Hepatocellular carcinoma (HCC)/hepatocarcinoma/hepatoma
Uncommon hepatic malignancy in children
Hepatoblastoma
Disease found primarily in children; idiopathic; related to aspirin therapy; usually occurs following recovery from viral infection
Reye syndrome
Most important drug related to hepatic toxicity
Ethanol
Caused by heavy and prolonged consumption of ethanol
Alcoholic cirrhosis
3 stages of alcohol-induced liver injury
- alcoholic fatty liver
- alcoholic hepatitis/liver fibrosis
- alcoholic cirrhosis
Alcoholic fatty liver with inflammation
Steatohepatitis
Amount of ethanol that causes one to be under the influence of alcohol
> 1000 mg/L
Amount of ethanol that causes CNS impairment/coma
3000 mg/L
Amount of ethanol that causes death
4000 mg/L
Reagent used in Muelengracht mtd for icterus index
NSS
Solution used for comparison in Newberger mtd for icterus index
Sodium citrate
3 substances that interfere with icterus index
- carotene
- xantophyll II
- hemoglobin
Property used to differentiate conjugated and unconjugated bilirubin
Solubility
3 fractions comprising total bilirubin
- conjugated bilirubin
- unconjugated bilirubin
- delta bilirubin
Preferred sample for Malloy-Evelyn procedure
Serum
Number of days serum/plasmais stable for bilirubin at room temperature
2 days
Number of days serum/plasma for bilirubin is stable at 4 degrees Celsius
7 days
Number of days that serum/plasma is stable for bilirubin at -20 degrees Celsius
Indefinite
4 reagents in Malloy-Evelyn procedure
- diazo reagent (sulphanilic acid & sodium nitrite)
- 50% methanol
- sodium acetate
- ascorbic acid
pH level of Malloy-Evelyn procedure
pH 1.2
Color of product in Malloy-Evelyn procedure
Red-purple
Wavelength of Malloy-Evelyn procedure
560 nm
Most common accelerator used in Malloy-Evelyn procedure
50% Methanol
4 reagents of the Jendrassik-Grof method
- diazotized sulphanilic acid (lphanilic acid & sodium nitrite)
- caffeine sodium benzoate
- sodium acetate
- ascorbic acid
Color of initial product in Jendrassik-Grof method
Purple
Accelerator in Jendrassik-Grof method
Caffeine sodium benzoate
Terminates the reaction of the aliqouts with the diazo reagent in Jendrassik-Grof method
Ascorbic acid
Solution used to alkalinize the solution in Jendrassik-Grof method
Alkaline tartrate solution
Color of final product in Jendrassik-Gtof method
Blue
Wavelength used in Jendrassik-Grof method
600 nm
Colorless end product of bilirubin metabolism
Urobilinogen
Urobilinogen that is oxidized by intestinal bacteria; brown pigmented
Urobilin
3 reagents for Ehrlich’s method for urine urobilinogen
- Ehrlich’s reagent (p-dimethylaminobenzaldehyde)
- ascorbic acid
- saturated sodium citrate (NaCH3COO)
Reagent in Ehrlich’s method that serves as reducing agent to maintain urobilinogen in a reduced state
Ascorbic acid
Reagent in Ehrlich’s method that stops the reaction and minimizes the combination of other chromogens
Saturated sodium citrate (NaCH3COO)
Color of product of Ehrlich’s method for urine urobilinogen
Red
Specimen for Ehrlich’s method for urine urobilinogen
Fresh 2-hour urine specimen
4 substances that interfere with urine urobilinogen measurement (Ehrlich’s method)
- 5-hydroxyindoleacetic acid
- porphobilinogen
- sulfonamides
- procaine
Sample in fecal urobilinogen
Aqueous extract of fresh feces
Reagent used for fecal urobilinogen that reduces urobilin to urobilinogen
Alkaline ferrous hydroxide (Fe(OH)2)
Color of product for fecal urobilinogen
Red
2 clinical significance of increased urobilinogen
- hemolytic disease
- defective liver cell function (hepatitis)
2 clinical significance of absence of urobilinogen
- biliary obstruction
- hepatocellular disease
Test used for bile salts
Hay Test
Used in Hay Test to detect the presence of bile salts
Sulphur powder
Interpretation of Hay test when sulphur powder floats
Bile salts absent
Interpretation of Hay test when sulphur powder sinks to the bottom
Bile salts present (obstructive jaundice)
Buffer in Evelyn-Malloy procedure
Sodium acetate
Stop solution in Evelyn-Malloy method
Ascorbic acid
Tested for the synthetic function of the liver
- total protein
- albumin
- alpha-globulin
- prothrombin time
2 tests for testing the excretory function of the liver
- Bromsulphalein test
- Rose Bengal Test
2 methods under Bromsulphalein test
- Rosenthal
- Mc Donald
Element used in Rose Bengal Test
Tagged Iodine 131
Color of urine foam positive for bilirubin
Yellow
Urine color positive for bilirubin
Brown to amber
4 tests for urine bilirubin
- Foam test
- Urine color inspection
- Fouchet’s test or Harrison Spot Test
- Diazotization Test
Used to precipitate bilirubin in Fouchet’s test
BaCl2
Reagent in Fouchet’s test/Harrison Spot test
FeCl3 and TCA
Color of final precipitate in Fouchet’s test/Harrison Spot test; positive for bilirubin
Green precipitate
Test used to determine detoxification function
Quick’s Test/Hippuric Acid Test
Consumed by patient in Quick’s test/Hippuric acid test
Sodium benzoate meal
In normal patients, what percentage of the benzoate meal in Quick’s test is excreted within 1 hour?
40%
Inflammation of the liver
Hepatitis
2 hepatitis types acquired through the fecal-oral route
A and E
Causes Hepatitis A
Picorna virus
Causes Hepatitis B
Hepadna virus
Causes Hepatitis C
Flavivirus
Causes Hepatitis D
Delta agent (needs HBsAg)
Causes Hepatitis E
Hepevirus
2 cardinal features of cirrhosis
- fibrosis
- nodules
Prevents regeneration of the liver
Fibrosis
Elevated in Reye’s Syndrome
Elevated liver function tests except bilirubin
Causes Hepatitis F
Toga virus
Causes Hepatitis G
G-B virus
MOT of Hepatitis A&E
Fecal-oral route
MOT of Hepatitis B, C, and D
Parenteral, sexual
Classification of hepatitis based on etiology
- viral hepatitis (B, C, D)
- alcoholic
- toxic
- metabolic (hemochromatosis, Wilson’s disease, galactosemia)
- autoimmune
- cardiac
- biliary
Classification of cirrhosis based on morphology
- micronodular
- macronodular
- micromacronodular (mixed cirrhosis)
- septal
Classification of cirrhosis based on activity and spread of progression
- active (rapidly, slowly, latent)
- nonactive
Classification of cirrhosis based on the course of the disease
- compensation (hepatic encephalopathy)
- subcompensation (hepatic encephalopathy stages I-II, ascites controlled by drugs)
- decompensation (hepatic encephalopathy stage III, ascites not controlled by drugs)
Classification of cirrhosis based on complications
- hepatic coma (precoma)
- bleeding esophageal stomach/hemorroidalvarices
- bacterial peritonitis
- portal vein thrombosis
- primary cancer of the liver
A congenital condition due to maternal steroids causing increased B1 becuase of a defect in UDPGT
Lucey Driscoll
Solution used for comparison in Muelengracht mtd for icterus index
0.01% K2Cr2O7
Advantages of Jendrassik-Groff mtd over Evelyn-Malloy mtd for bilirubin
- insensitive to pH changes
- insensitive to a 50-fold variation in protein conc
- adequate optical sensitivity even with low bilirubin conc
- minimal turbidity and with constant serum blank
- not affected by Hb up to 750 mg/dL
Normal range for conjugated bilirubin
0 - 0.2 mg/dL
Conjugated bilirubin is increased during
Obstructive jaundice
Normal range for unconjugated bilirubin
0.2 - 0.8 mg/dL
Unconjugated bilirubin is increased during
Hemolytic jaundice
Normal range for total bilirubin
0.2 - 1.0 mg/dL
Total bilirubin is increased during
Hepatocellular jaundice
Sources of error for bilirubin measurement
- hemolysis
- exposure to light
- lipemia
- lipochrome