hepatic Flashcards
what is special about the blood supply to the liver
Dual supply
Portal Circulation
Portal vein
Systemic Circulation
Hepatic Artery
what is the functional unit of the liver
hepatocytes
functions of the liver
-produces bile acids for excretion of bile (degrades cholestrol to bile acis which mix with bile and drains into gall bladder, emulsifies fats into chyme)
-involved in carbohydrate metabolism (glucogeneosis, glycogenesis, glycogenolysis)
-involved in protein metabolism (plasma protein, albumin and globulins)
-involved in lipid metabolism (FA, triglycerides, cholestrol)
-produces coaggulation factors (may cause patient to bleed out)
-breaks down haemaglobin
-detoxification
-site of ammonium fixation (ammonium-> urea/amino acid)
-storage (glucose, triglycerides, iron)
-immulogical filter
what is glycogenesis (genes= to create)
formation of glycogen from glucose
what is glycogenolysis
breakdown of glycogen in glucose
what is gluconeogenesis (neo= new)
synthesis of glucose from certain amino acids, lactate or glycerol
what is icterus
medical time of jaundice
happens when hemaglobin is metabloised into billirubin-> this causes they yellow colour
explain bilirubin metabolism
breakdown of rbc: form heam and globin
heam breaks down into iron and biliverdin (green colour)
biliverdin converts into bilirubin (uncojugated)
in the liver, bilirubin in cojugated with albumin (albumin cause it to become conjugated)
what is the rls between liver disease and bilirubin
liver disease cause loss of conjugated bilirubin into bloodstream cause jaundice/ icterus appearance
steps to diagnosing liver disease
history: anorexia, weight loss, bleeding
physical examination: icterus, orangey faeces
neurological signs ( seizures , blindness, abnormal behaviour)
- diagnostic test: CBC, biochemistry, xray, ultrasound)
what is the indication of heaptobillary disease
elevated liver enxymes
what are the two different types of liver enzymes
hepatocellular markers: enzymes ALT& AST are released with hepatocyte damage
cholestatic markers: billary enzymes (ALP, GGT)
which biochemistry panel do we use
chem 10: ALT, ALP
chem 17: all four
what is ALT and what does it mean
alanine amino transferase (ALT)
very specific for liver disease, does not mean that liver disease is permanant, could mean its just damaged and can recover)
what us AST and what does it mean
asparate amino transferase (AST)
not as specific bc is present in both liver and muscles (cardiac and skeletal) (damge in muscle can also cause increased levels) damage to either will cause increase
what is ALP and what does it mean
Alkaline phosphate (ALP)
present in billary canaliculi cells of liver and in bone
can also increase bc of drugs such as corticosteriod and phenobarbitone
some breed may just have naturally high (Doesnt not mean liver disease)
what is ggt and what does it mean
Gamma glutamyl transferase (GGT)
marker of billary stasis (movement)
less specific that ALP
what is the most specific test to diagnose liver disease
serum bile acid test
what does an increase in serum bile acid mean
there is less blood flow to the liver or loss of functional heapatocyte
(bile acids are excreted in the bile in the duodenum, reabsorbed by the ileum and re- excreted by the liver)
how to perform bile acid serum test
- patient has to be fasted for 12hrs
-at 0hr, pre-prandial blood sample is drawn - patient is fed a high fat meal in hospital (must finish all the food)
- at 2hr post-prandial blood sample is drawn (food is in small intestine)