Clinical Biochemistry 1

Question 1

State how the liver is perfused with blood from two supplies.

Answer 1

• Via the hepatic portal vein carrying blood from the intestine prior to distribution to general circulation
• Via the hepatic artery, a branch of the aorta supplying oxygen and nutrients

Question 2

What are the physiological functions of the liver?

Answer 2

• Homeostasis
• Detoxification
• Glucose homeostasis
• Lipid homeostasis
• Protein synthesis & metabolism
• Bile acid metabolism & transport
• Hormone regulation
• Immunological function

Question 3

Where is the liver located?

Answer 3

• The right hypochondriac and extending to the epigastrium

Question 4

What are LFTs?

Answer 4

Liver Function Test - used as indicators for hepatic dysfunction

Question 5

State the standard parameters of LFTs.

Answer 5

• Alkaline phosphatase (AP)
• Alanine aminotransferase (ALT)
• Aspartate aminotransferase (AST)
• Gamma-Glutamyl transferase (GGT)
• Bilirubin
• Albumin
• Total protein

Question 6

What are the enzyme measurements?

Answer 6

1.Soluble cytoplasmic enzymes - AST & ALT
2.Membrane-associated enzymes - AP & GGT

Question 7

What is Alkaline Phosphate? (AP)

Answer 7

Term used to describe a widely distributed set of isoenzymes

Question 8

Where is hepatic AP produced?

Answer 8

Produced by hepatocytes, production is increased in patients with damage to the biliary system.

Question 9

Which diseases is AP increased?

Answer 9

1. Liver disease- hepatitis, cholestasis.
2. Bone disease-Paget’s, bone malignancy even just via growth- teenagers.
3. Pregnancy- often elevated at the end of pregnancy and beyond particularly if
   the mother breastfeeds.

Question 10

Where is aminotransferases widely distributed?

Answer 10

In liver, heart, pancreas, lung, RBCs and skeletal muscle

Question 11

Where is alanine aminotransferase found?

Answer 11

The liver, more specific to the liver than AST

Question 12

What does increased serum level indicate?

Answer 12

Hepatocellular damage

Question 13

Where is there a high conc of gamma-glutamyl transferase? (GGT0

Answer 13

Liver, kidneys, pancreas, intestine and prostate

Question 14

What disease is linked with GGT?

Answer 14

Sensitive indicator of hepatobiliary disease in
conjunction with raised AP

Question 15

What is albumin levels used to measure?

Answer 15

Hepatic functional capacity as most albumin is manufactured in the liver.

Question 16

Describe the albumin levels for Cirrhotic patients.

Answer 16

50% decrease in albumin levels

Question 17

In which conditions is albumin also altered?

Answer 17

Crohns disease
Malnutrition
Malignancy
Nephrotic syndrome

Question 18

What is a major function of the liver?

Answer 18

Manufacture plasma proteins - the main proteins are albumin and clotting factors

Question 19

What is INR?

Answer 19

The international normalised ratio (INR) blood test tells you how long it takes for your blood to clot.

Question 20

Describe the INR for patients with chronic or acute liver disease.

Answer 20

• Elevated INRs

Question 21

How can INR be used?

Answer 21

Paracetamol poisoning as a marker of hepatocellular damage

Question 22

What happens in those with jaundice?

Answer 22

1. INCREASED Production of bilirubin DECREASED uptake (pre-hepatic)
2. Decreased metabolism (intra-hepatic)
3. Decreased excretion (hepatic + extra-hepatic)

Question 23

What can unconjugated hyperbilirubinaemia cause?

Answer 23

• Haemolysis
• Gilberts syndrome
• Crigler-Najjar syndrome
• Drugs e.g. rifampicin

Question 24

What can conjugated hyperbilirubinaemia cause?

Answer 24

• Intra or extra-hepatic cholestasis
• Acute Hepatitis
• Cirrhosis

Question 25

What can elevated bilirubin cause?

Answer 25

• Jaundice
• Pale stools/dark urine
• Steatorrhoea
• Gynacomastia
• Spider naevi
• Acsites
• Oesophageal varices
• Pruritis
• Dupuytren’s contracture