Liver failure and Jaundice

Question 1

What is bilirubin?

Answer 1

Yellow pigment from the breakdown of haemoglobin

H2O insoluble

Question 2

Where is most bilirubin created or released?

Answer 2

Spleen

Where RBC destruction and repackaging happens

Question 3

How does bilirubin get to liver

Answer 3

Albumin binds to bilirubin, carries in blood to liver. Albumin release
Bilirubin enters hepatocyte.

Question 4

How does bilirubin become soluble

Answer 4

Conjugation (joining) to glucaronic acid using UDPGT from smooth ER
So now bound and now called
Diglucoronide billirubin/conjugated billirubin
So more soluble

Question 5

What is the total BR?

Answer 5

Free unconjugated and conjugated bilirubin

Question 6

What happens to conjugated bilirubin?

Answer 6

Transported across concentration gradient into bile canaliculi to GIT

Question 7

What is urobilinogens?

Answer 7

Formed by action of gut bacteria - H2O soluble colourless derivative of bilirubin

Question 8

Why is poo brown

Answer 8

In colon, bilirubin undergoes reduction by gut bacteria to stercobilinogen
Oxidised to stercobilin
Which is brown
So poo is brown

Question 9

What is jaundice?

Answer 9

Excess bilirubin in the blood which is >34-50microM/L

Question 10

What is cholestasis?

Answer 10

Slow or sluggish bile flow

Normally results in jaundice but jaundice doesn’t necessarily mean cholestasis

Question 11

What three groups are the causes of jaundice divided into?

Answer 11

Pre-hepatic
Hepatic
Post-hepatic

Question 12

What causes pre-hepatic jaundice?

Answer 12

Before reaches liver - too much bilirubin being produced too fast
Haemolysis - too fast RBC death
Massive tranfusion
Haematoma resorption
Ineffective erythropoiesis

Question 13

What is hepatocellular jaundice

Answer 13

Normal bilirubin entering liver
There is liver disease/illness killing hepatocytes
Less conjugation
Less secretion

Question 14

What causes hepatocellular jaundice

Answer 14

Anything causing liver failure
paracetamol overdose
Chronic liver failure - viral hepatitis B/C
alcohol
sepsis in liver
drugs

Question 15

How to distinguish between hepatic and pre-hepatic jaundice

Answer 15

pre-hepatic -> liver is normal but in hepatic the liver is dying

Question 16

What is post hepatic jaundice aka obstructive

Answer 16

Liver fine
Bilirubin amount fine
Physical obstruction of bile flow into duodenum so less bilirubin enter gut so bilirubin levels will increase

Question 17

What are causes of post hepatic jaundice aka obstructive

Answer 17

Gall stones

Cancer eg gall bladder/bile duct/tumour on dead of pancreas pressing on duodenum

Question 18

Will the majority of bilirubin be conjugated or unconjugated in pre-hepatic, hepatic and post hepatic jaundice?

Answer 18

Pre-hepatic unconjugated
Hepatic unconjugated
Post-hepatic conjugated

Question 19

What happens to poo and urine in obstructive jaundice

Answer 19

Less brown bc less bilirubin so less stercobilogen
pale
Urine dark, as bilirubin tries to get out by kidneys

Question 20

What is the commonest hereditary cause of increased bilirubin

Answer 20

Gilbert’s Syndrome

Question 21

What is Gilbert’s syndrome caused by

Answer 21

Elevated unconjugated bilirubin in blood stream
Caused by less glucuronidation activity of the enxyme UDPGT-1A1 so conjugates bilirubin slower
No serious consequences

Question 22

What is liver failure?

Answer 22

Amount of hepatocytes destroyed more then hepatocytes regenerated

Question 23

What are examples of stuff livers do?

Answer 23

Detoxificaition
Glycogen storageProduction of clotting factors
Immunological function and globulin production
Maintenance of homeostasis - albumin making