LECTURE 19 - Test of liver function

Question 1

What are the intracellular/ intrahepatic enzymes

Answer 1

ALT and AST

Question 2

What are the bilary/ cholestatic enzymes

Answer 2

ALP
GGT
Billirubin

Question 3

what percentage of bilirubin is uncongugated/indirect

Answer 3

85%

Question 4

what is insoluble billirubin bound to

Answer 4

albumin

Question 5

what form of bilirubin is soluble

Answer 5

bilirubin glucuronide

Question 6

what does the bacteria in the gut convert billirubin gluconoride into

Answer 6

urobillinogen

Question 7

what percentage of billirubin is conjugated/direct

Answer 7

15%

Question 8

what is uncongugated billirugin

Answer 8

billirubin bound to albumen

Question 9

what is conjugated billirubin

Answer 9

billirubin glucuronide

Question 10

what happens to urobilinogen

Answer 10

either excreted in faeces or reabsorbed into the hepatic circulation

Question 11

what are the 2 pathways of billirubin glucuronide

Answer 11

either into the bile where it is converted by bacteria in the gut into urobilinogen

OR

enters the bloodstream as billirubin glucuronide

Question 12

what happens to billirubin when haemolysis occurs

Answer 12

billirubin bound to albumin increases and so dies urobiliongen which means it is more present in faeces and urine

Question 13

what is ALT involved in

Answer 13

in making pyruvate in gluconeogenesis

Question 14

where is ALT found

Answer 14

in the hepatocytes and the cytosol

Question 15

which enzyme is the most liver specific

Answer 15

ALT

Question 16

when is ALT high

Answer 16

in early and late hepatitis

Question 17

What is AST involved in

Answer 17

in making glutamate in gluconeogenesis

Question 18

where is AST foun

Answer 18

in hepatocytes and in cytosol and mtochondria

Question 19

which has a shorter halflife AST or ALT

Answer 19

ALT has a longer half life (48hrs vs 8hrs)

Question 20

when is AST high

Answer 20

in hepatitis

Question 21

which enzymes are of billary origin

Answer 21

GGT and ALP

Question 22

when is ALP high

Answer 22

in obstruction and inflammation of liver billary syst

Question 23

When is GGT high

Answer 23

2-3 days after alcohol consumption, due to inflamation/obstruction of billary systm

Question 24

when is billirubin elevated

Answer 24

in hepatitis or cancer

Question 25

what does a elevated billirubin indicate

Answer 25

that your liver isn’t clearing billirubin properly

Question 26

what does the prothrombin ratio refect

Answer 26

reflects clotting facor sysnthsis- rise indicates Vitamin K deficiency or liver faliure

Question 27

what are the sources of albumin

Answer 27

liver is the only source

Question 28

when does albumin levels fall

Answer 28

indicates impaired liver function

• decreased synthesis (cirrhosis)
• increased loss (eg kidney)
• illness

Question 29

what does high globulin levels reflect

Answer 29

inflammation

Question 30

when are globulin levels high

Answer 30

with chronic hepatitis/ cirrhosis

Question 31

what does it mean if glucose is though

Answer 31

liver damage

Question 32

what are the 2 categories of the causes of jaundice

Answer 32

unconjugated/ indirect

conjugated/ direct

Question 33

what are the unconjugated/indirect causes of jaundice

Answer 33

haemolysis,

Gilbert’s syndrome= decrease in uptake of billirubin

Question 34

what are the conjugated/ direct causes of jaundice

Answer 34

cholestasis- when bile can’t flow from the liver to the duodenum

obstruction inside liver (hepatitis, cirrhosis, masses)

obstruction outside liver- gall stones, billary/ pancreateic cancer, pancreatitis

Question 35

what is Gilbert’s syndrome

Answer 35

decrease in uptake of billirubin
other liver function tests will be normal
illness/ fasting will worsen

Question 36

common causes of viral hepatitis

Answer 36

infectious mono

hep a and b

Question 37

causes of LFT abnormaliites

Answer 37

fatty liver
viral hepatitis
alchol
haemochromatosis

Question 38

what does increased ammonia indicate

Answer 38

decreased liver function