week 2

Question 1

list liver functions

Answer 1

amino acid, carbohydrate and lipid metabolism
storage of proteins, glycogen, vitamins and metals
plasma protein and enzyme synthesis
detoxification
production of bile
immune functions

Question 2

components of portal triad

Answer 2

hepatic artery
portal vein
bile duct

Question 3

three features of cirrhosis

Answer 3

diffuse process with fibrosis and nodules

Question 4

components of bile

Answer 4

bile pigments (bilirubin - haemoglobin breakdown product)
bile acids/salts - cholesterol-based 
mucin
bicarbonate
cholesterol, phospholipids

Question 5

haem breakdown to bilibrubin

Answer 5

haem broken down to biliverdin by haem oxygenase
biliverdin converted to bilirubin by biliverdin reductase
unconjugated must be bound to albumin

Question 6

conjugation of bilirubin

Answer 6

ligandin presents UB to glucuronic acid
occurs in liver
UB enters hepatocytes via sinusoidal bilirubin transporter
UDP glucuronyl transferase converts UB to CB

Question 7

pathway of conjugated bilirubin out of body

Answer 7

bilirubin to urobilinogen in small intestine
some goes to large intestine and is converted to stercobilin - in faeces
some goes to liver via portal vein and is converted tp urobilin in kidney - in urine

Question 8

pre-hepatic jaundice

Answer 8

elevated haemolysis
more haemoglobin 
more bilirubin produced - unconjugated  - hyperbilirubinarmia 
large increase in UB
CB is normal or slight increase
no bilirubin in urine
increase of urobilinogen and stercobilin

Question 9

hepatic jaundice

Answer 9

could be:
impaired uptake of CB
impaired conjugation of bilirubin
impaired transport of CB into bile canaliculi
increase in CB and UB
increase in bilirubin and urobilin in urine
stercobilin normal

Question 10

post-hepatic jaundice

Answer 10

obstruction of hepatic, cystic or common bile duct - cholestasis
gall stones 
pancreatitis - swelling can block
pancreatic tumours
UB normal 
large increase in CB 
large increase of bilrubin in blood
urobilin in urine is absent 
stercobilin in faeces is absent

Question 11

carbohydrate metabolism in the liver

Answer 11

storage as glycogen and released in glycogenolysis
gluconeogenesis - synthesis of glucose from other sources eg lactate, pyruvate, glycerol, alanine
glucose as an energy substrate - glycolysis, citric acid cycle, synthesis of FA and TG
conversion of fructose and galactose to glucose phosphates

Question 12

lipid metabolism in the liver

Answer 12

mitochondrial beta oxidation of short chain fatty acids
synthesis of FA, TG, CHOL, phospholipids and lipoproteins
cartnitine acyl transferase allows FAs to enter mitochondria

Question 13

protein metabolism in the liver

Answer 13

most circulating proteins are synthesised wholly or largely by liver
albumin, glycoproteins
glycation of protein

Question 14

breakdown of RBCs

Answer 14

hb broken down into
haeme - converted to bilirubin
globins - broken into amino acids and recycled
iron - bound by transferrin and returned to iron stores in the liver or bone marrow

Question 15

inherited metabolism disease presenting with acute onset liver failure

Answer 15

neonatal to 3 years
episodic vomitting since neonatal period, possible failure to thrive, possible family history
abnormal stress such as infection, fasting, exercise
progressive encephalopathy and anicteric multisystem failure and acidosis

Question 16

what can be measured in a LFT

Answer 16

bilirubin
albumin
alanine aminotransferase (ALT)
aspartate aminotransferase (AST)
alkaline phosphatase
gamma glutamyl transferase (y-GT)
total protein

Question 17

role of AST and ALT in gluconeogenesis

Answer 17

they catalyse the transfer of amino groups from aspartic acid or alanine to ketoglutaric acid to produce oxaloacetic acid and pyruvic acid respectively

Question 18

function of (y-GT)

Answer 18

responsible for the transfer of glutamyl groups from gamma-glutamyl peptides to other peptides or amino acids

Question 19

LFTs in hepatocellular disease v cholestatic disease

Answer 19

hepatocellular - AST >3x url, ALP<2x url

cholestatic disease - AST <3x url, ALP >2x url

Question 20

gilberts syndrome

Answer 20

genetic defect on chromosome 2 for the locus coding for the UGT-1A1 protein
this protein is involved in converting UB to CB

Question 21

5 Fs for gall stones

Answer 21

female 
fair
fertile
forty
fat

Question 22

3 main types of gallstones

Answer 22

cholesterol stone - usually solitary, oval and large
bile pigment stone - multiple, irregular, hard and associated with chronic haemolysis
mixed stones - most common, multiple, multi-faced, laminated structure with layers of cholesterol, bile pigment and calcium salts

Question 23

pathology of gallstones

Answer 23

cholesterol supersaturation
biliary stasis - occurs during periods of fasting or starvation
increased bilirubin secretion - can be due to increased RBC breakdown in disease or failure of hepatic conjugation

Question 24

acute cholecystitis

Answer 24

impacted stone in gallbladder leading to GB oedema/inflamation and bacterial infection
raised inflammatory markers, sometimes normal LFT, can have jaundice
murphy’s sign - extreme tenderness over GB fundus

Question 25

curvoisier’s law

Answer 25

in the presence of a palpable enlarged gallbladder which is non-tender and accompanied with mild painless jaundice, the cause is unlikely to be gallstones

Question 26

LFTs in biliary obstruction

Answer 26

ALP increased early - often associated with rise in GGT
bilirubin rises steadily
AST/ALT can be elevated in obstructive jaundice bus is much less prominent