Lecture 8-9 (Liver)

Question 1

Major functions of the liver

Answer 1

Carbohydrate metabolism 
Fat metabolism 
Protein metabolism 
Hormone metabolism 
Drugs and foreign compounds 
Storage 
Metabolism and excretion of bilirubin

Question 2

Metabolic pathway of bilirubin

Answer 2

Hemolysis gives unconjugated bilirubin

Unconjugated becomes conjugated in hepatocyte

Small intestine: conjugated bilirubin becomes urobilinogen which is excreted in feces (90%) and urine (10%)

Question 3

Name abnormalities of bilirubin metabolism

Answer 3

Gilberts
Crigler-Najjar
Rotor
Dublin-Johnson

Question 4

Conjugated bilirubin is __ soluble

Unconjugated bilirubin is __ soluble

Answer 4

Water

Lipid

Question 5

Principle of evelyn-malloy procedure

Answer 5

Bilirubin + diazo = azobilirubin which can be measured colormetrically

Unconjugated bilirubin needs addition of alcohol to interact with diazo

Question 6

Tests to measure bilirubin

Answer 6

Jendrassik-Grof procedure

Evelyn-malloy procedure

Question 7

Do liver function test indicate there is something wrong with the liver

Answer 7

No.

However normal LFTs don’t mean the liver is normal.

Question 8

What are the most used markers of hepatocyte injury

Answer 8

Aspartate aminotrans - ferase (AST)
Alanine aminotransaminase (ALT)

ALT - cytosolic
AST - cytosolic & mitochondrial

Question 9

Example where AST & ALT lack sensitivity in detecting chronic liver disease

Answer 9

Hepatitis C
Serum ALT correlates only moderately well

Found in skeletal muscle too so could be increased after muscle injury

Question 10

What happen enzymes of the liver in necorsis/hepatitis/injury/ischemic

Answer 10

Enzymes leak into circulation

Question 11

Which enzyme rises more after toxic liver injury ALT or AST

Answer 11

ALT

Question 12

What is cholestasis

Answer 12

Lack of bile flow

Question 13

What does cholestasis result from

Answer 13

Blockage of bile ducts or from disease that impairs bile formation in the liver itself

Question 14

What rises in cases of cholestasis

Answer 14

AP and gamma glutamyltransferase (GGT)

Question 15

Other than cholestasis why would AP levels rise

Answer 15

In 3rd trimester of pregnancy because of a form of the enzyme produced in the placenta

Question 16

Do healthy persons have detectable conjugated bilirubin in their blood

Answer 16

No.

Conjugated bilirubin is conjugated with glucuronic acid in hepatocytes to increase water solubility and transported into bile

Question 17

What factors make albumin concentrations difficult to interpret

Answer 17

Functional capacity of liver
Half life of albumin in serum (3 weeks)
2/3 of total body albumin ECF

Question 18

Reasons for low serum albumin (nonhepatic)

Answer 18

Proteinuria

Acute/chronic inflammatory state

Question 19

Indicators of how well the liver functions

Answer 19

Bilirubin
Albumin
Prothrombin time

Question 20

Causes of acute liver disease

Answer 20

Poisoning
Infection
Inadequate perfusion

Question 21

Most common poisons affecting liver

Answer 21

Paracetemol

Carbon tetrachloride

Question 22

What happens in the case of hepatic failure

Answer 22

Severe metabolic acid-base disturbances
Hypoglycaemia
Renal failure due to exposure of toxins usually metabolised by liver
Failure to synthesis clotting factors - leads to haemorrhage

Question 23

Three forms of liver damage

Answer 23

Alcoholic fatty liver
Chronic active hepatitis
Primary biliary cirrhosis

Question 24

Definition of cirrhosis

Answer 24

Disease characterised by the replacement of active liver tissue with an inactive fibrosis mass

Question 25

Most common causes of cirrhosis

Answer 25

Chronic excess alcohol ingestion
Viral hepatitis
Autoimmune disease

Question 26

Terminal stage signs of cirrhosis

Answer 26

developing jaundice
encephalopathy
ascites
bleeding tendencies terminal liver failure