Investigation of the liver

Question 1

What is the function of the liver?
Carbohydrates
Proteins
Lipids
Excretion / detox
Miscellaneous

Answer 1

1) Carbohydrates:
- Glycogen storage / synthesis

2) Proteins:
- synthesis and metabolism
- clotting factors
- urea synthesis

3) Lipids
- Lipoprotein and cholesterol synthesis
- fatty acid metabolism
- BILE ACID SYNTHESIS / METAB

4) Excretion/ detoxification:
- DRUGS
- BILE ACID
- BILIRUBIN (unconjugated to conjugated)

5) Miscellaneous
- iron storage
- Vit A, D, E and B12 storage and metabolism

Question 2

What are the common tests of liver function?

Answer 2

• Alkaline phosphatase
• ALT (alanine aminotransferase)
• Bilirubin
• Total protein
• GGT (gamma glutamyl transferase)

Question 3

Prothrombin time is used as a measure of …..

Answer 3

Vitamin K metabolism

Question 4

What markers are used for hepatocyte damage?

Answer 4

ALT and AST are found in cells and only released by cellular damage, so increased ALT (alanine) and aspartate (AST) indicate hepatocyte damage

Question 5

Which is a more specific marker for the liver AST or ALT>

Answer 5

ALT is more specific than AST becuase AST is also found in muscle and RBCs.

Question 6

How is biliary tract damage identified?

Answer 6

• Impaired excretory function (ie increased conjugated bilirubin)
• increased synthesis of enzymes by cells that line the bile canaliculi.
• elevated ALP (alkaline phosphatase)
• elevated gamma glutamyltransferase

Question 7

What is the cause of increased alkaline phospatase?

Answer 7

• cholestasis

- cirrhosis

Question 8

isolated ALP enzymes can be secreted from….?

Answer 8

Liver and bone

Question 9

why is gamma glutamyltransferase elevated in biliary tract damage?

Answer 9

alcohol
fatty liver
structural damage

can also be raised in :
heart failure
prostatic disease
pancreatic cancer
kidney damage

Question 10

what bilirubin level causes jaundice?

Answer 10

above 40umol/L

Question 11

Gilberts and Crigler- Najjar are inherited diseases. what do they cause?

Answer 11

Causes jaundice by

decreasing activity of UDP glucuronyl transferase (the enzyme that conjugated bilirubin.

Question 12

What is elevated AST / ALT and normal ALP indicative of in jaundice?

Answer 12

Hepatitis is the cause of jaundice.

Question 13

What is normal AST/ALT and elevated ALP indicative of in jaundice

Answer 13

Obstruction is cause of jaundice

Question 14

Dark urine and pale stools is a sign of?

Answer 14

Post hepatic obstruction causing jaundice

Question 15

What are the systemic effects of liver disease?

Answer 15

1) jaundice
2) excess oestrogen
- gynaecomastia
- spider naevi
- liver palms
- testicular atrophy
3) brusiing
4) pigmentation
5) clubbing
6) oedema
7) ascities
6) encephalopathy
8) osteoporosis (Vit D activation limited)