liver function Flashcards
what holds the liver in place
ligaments
segments separated by falciform ligament
portal vein blood supply
75%
hepatic artery blood supply
25%
hepatoctes
liver function cells
Kupfer cells
liver-specific macrophages
list the biochemical functions of the liver
- excretion/secretion
- storage
- metabolism
- detoxification
what happens to water sol bilirubin
conjugated bilirubin
secretated from hepatocyte into bile canaliculi
glycogenesis
store glucose as glycogen
glycogenolysis
breakdwown of glycogen
gluconeogensis
creatoin of glucose from non sugar carbon substrates
lipid metabolism
free fatty acids-> acetyl CoA -> trigs, phospholipids, cholesterol
describe the two mechanisms for detoxification of waste products
- binds material irreversibly = inactivated
- chemically modifies compound to be excreted
describe jaundice generally
retention of bilirubin (3-5mg/dL) causing yellowing of skin
- classified based on site of disorder
prehepatic jaundice
- increased amount of bilirbin sent to liver
- hemolytic anemia (acute/chronic)
- unconjugated hyperbilirubinemia
- increased urobilinogen in urine
posthepatic jaundice
- biliary obstructive disease
- bilirubin conjugated but can’t be excreted
- bile not through intestines = pale poop
hepatic jaundice
- disorder of bilirubin metabolism
- transport defects
- hepatocellular injury or destruction
gilberts syndrome
- hepatic jaundice
- benign recessive
- defect conjugation system = intermittent unconjugated hyperbilirubinemia
crigler-Najjar syndrome
- hepatic jaundice
- nonhemolytic hyperbilirubinemia
- either absence or defiency of enzyme for conjugation
–> can’t conjugate bilirubin
Dubin-Johnson syndrome
- hepatic jaundice
- conjugated hyperbilirubinemia
- ability to remove conjugated bilirubin impacted (can’t remove)
- delta bilirubin = conjugated and albumin bound
rotor syndrome
- hepatic jaundice
- bilirubin less effectively taken up and removed
- the movement rotor non functional
- use of ALP and GGT to differentiate from obstruction
physiologic jaundice
- hepatic jaundice
- common in first week of life
- deficiency in UDPGT
kernicterus
physiologic jaundice
unconjugated bilirubin in neonate that can deposite in brain
describe Cirrohis
- scar tissue replaces normal tissue
- blocks flow of blood
- prevents normal liver function
which type of tumor is more common in liver
metastatic (vs primary)
most common primary cancer in liver
hepatocellular carcinoma (HCC)
reye’s syndrome
found in children following viral syndrome w/ aspirin
-> increase in AST and ALT
most common mechanism of alcohol related injury to liver
immune mediated injury to hepatocytes
fatty liver disease
- from alcohol
- mild with slight liver marker elevations: AST, ALT and GGT
alcoholic hepatitis
- serum proteins decrease (albumin)
- increase AST, ALT, GGT, ALP and bilirubin
AST/ALT ratio in alcoholic hepatitis
> 2
alcoholic cirrhosis
- increase in liver markers
- decreased albumin
- need liver biopsy
describe the malloy-evelyn procedure for bilirubin assesment
- diazo reagent
- methanol accelerator
describe the jandrassik- Grof method of bilirubin assesment
- more commonly used
- diazo binds conjugated bilirubin only
- caffeine-benzoate accelerator gives total bilirubin
what does increased levels of urinary urobilinogen indicate
hemolytic disease
describe the role of liver enzyme measurment for functionality
- differentiates hepatocellular (functional) from obstructive (mechanical)
describe alkaline phosphatase
- differentiates heptobiliary disease and osteogenic bone disease
- high ALP seen in extrahepatic biliary obstruction
describe 5’-nucleotidase
- significantly elevated in hepatobiliary disease
- not ordered often
describe GGT
- biliary obstruction measurment
- most sensitive hepatic enzyme indicator for liver disease
test for assessing synthetic ability of liver
serum protein
test to measure decreased protein synthesis
decreasing albumin
what Ig is seen in primary biliary cirrhosis
IgM
what Ig is seen in alcoholic cirrhosis
IgA
- A for alcohol
describe nitrogen metabolism testing
converts to urea -> ammonia level reflects liver function