Liver Function & Disease Flashcards Preview

Clinical Chemistry > Liver Function & Disease > Flashcards

Flashcards in Liver Function & Disease Deck (41)
Loading flashcards...
1

Portal vein

brings nutrients & 75% of blood supply

2

Hepatic artery

brings 02 & supplies 25% of blood to liver

3

Hepatocytes

80% of liver space, do liver jobs & also facilitate regeneration

4

Kupffer cells

macrophages that line sinusoids, phagocytic cells engulf bacteria, toxins, debris etc

5

Stellate cells

contain lipid droplets, when they are activated the lipids begin to deposit in the sinusoid & fibrotic tissues -> cirrhosis

6

Liver functions (4)

excretory & secretory
synthesis
detoxification & drug metabolism
storage

7

waste products & where they go

bilirubin, bile acids, cholesterol, bile pigments & other wastes get excreted in the bile that goes to the gall bladder & then small intestine

8

Heme degradation

heme from hemoglobin is degraded to biliverdin & then to bilirubin
this is insoluble & cannot be removed by kidneys

9

unconjugated bilirubin transporter

albumin to the liver sinusoidal spaces

10

location of bilirubin conjucation & carrier

bilirubin is carried by ligandin in hepatocytes to ER where bilirubin is conjugated

11

conjugation enzyme for bilirubin

UPD-glucuronyl transferase

12

conjugated bilirubin path

water soluble & most leaves the hepatocyte via bile ducts to go to gall bladder -> common bile duct -> small intestine
help in the emulsification of fats & broken down by gut bacteria to form urobilinogen then urobilin

13

reabsorbed urobilinogen goes where?

reabsorbed urobilinogen from the small intestine can go from the plasma to the urine through the kidneys

14

major exit route for bilirubin

mostly out via feces

15

Malloy-Evelyn

uses diazo reaction & 50% methanol accelerator to measure serum/plasma bilirubin
cannot use plasma specimen bc alcohol will precipitate proteins

16

Jendrassik-Grof

uses diazo reaction & caffeine-benzoate-acetate accelerator to measure serum/plasma bilirubin

17

total bilirubin

includes conjugated bilirubin & unconjugated bilirubin

18

conjugated bilirubin methods

does not use caffeine or alcohol (only measures what is already soluble)

19

reasons why J-G method is preferred

not affected by pH
insensitive to 50x change in protein
maintains optical sensitivity even @ low [bilirubin]
minimal turbidity & relatively constant serum blank
not affected by hemoglobin up to 759mg/dl

20

specimen for bilirubin

free of hemolysis & lipemia
KEEP AWAY FROM LIGHT

21

how does the liver stabilize glucose concentrations

absorbs glucose for own use
circulates glucose for peripheral tissues
stores glucose as glycogen
can make glucose from non-CHO sources

22

lipid synthesis by liver

makes VLDL, cholesterol
removes lipids from circulation= chylomicrons & HDL

23

protein synthesis by liver

synthesizes proteins other than immunoglobulins
makes coag proteins, albumin, globulins etc
stores amino acids for use or degradation

24

Liver detoxification

liver 1st pass effect allows liver to remove toxic/foreign compounds before they enter blood & circulate
removes bilirubin & ammonia
uses oxidation, reduction, hydrolysis, hydroxylation, carboxylation, demethylation via CYTOCHROME p-450 isoenzymes

25

jaundice

observable when bilirubin >3.0 mg/dl
prehepatic : increased RBC breakdown; major increase in unconjugated
hepatic- usually increase in conjugated
post hepatic- usually obstruction of bile duct (both elevated)

26

Gilbert's disease

not pathologic, elevation in unonjugated bilirubin
intermittent increase in unonjugated bili in ABSENCE OF HEMOLYSIS
reduction of UDP-glucuronyl transferase activity ~30%

27

Crigler-Najjar syndrome

2 types of UDP defect
type1: no UDP enzyme: fatal
type2: partial absence of enzymes

28

Dubin-Johnson syndrome

increased conjugated bilirubin
defect in MDR2/cMOAT or liver ability to remove & excrete conjugated bilirubin & cannot leave the liver

29

Rotor syndrome

unknown defect
increase in conjugated bilirubin
hepatic jaundice

30

post hepatic jaundice

often due to biliary obstruction: gallstones/tumors
labs: increase total bili & increased unconjugated bili