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Flashcards in liver Deck (71)
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1

role of fetal liver

major site of hematopoiesis in fetus: mesodermal hematopoietic stem cells migrate from mesonephros → to liver at 3 wk GA (source of fetal blood cell until BM at 28 wks GA)

2

portal triad

portal vein
hepatic artery
bile ductule

3

blood supply to liver

portal vein (from mesenteric veins, gastric vein): toxins + nutrition from GI
hepatic artery: O2 blood

4

hepatocytes role

make proteins
energy, vitamin, mineral storage
metabolize drugs/toxins
make bile → dump bile into bile canaliculi (opposite flow to sinusoid flow → bile ductule → hepatic duct → common hepatic duct...)
excrete bilirubin

5

zone affected first by ischemia + hypotension

zone 3: pericentral vein zone (farthest from O2 blood source - hepatic artery)

6

zone affected first by viral hepatitis

zone 1: periportal zone (next to portal vein)

7

zone most sensitive to metabolic toxins (acetaminophen overdose, site of alcoholic hepatitis)

zone 3: pericentral vein zone

8

zone with highest concentration of P450 enzymes

zone 3: pericentral vein zone

9

examples of proteins made by liver

coag factors
complement
albumin
apolipoproteins: lipid transport
transferrin: iron transport
ceruloplasmin: copper transport
others:
cholesterol
phosopholipids

10

examples of drug + toxin metabolism of liver

P450 enzymes
UDP glucoronyl transferase
ALT and AST: transaminases
steroid hormones → inactive metabolites (need for breakdown of estrogen, progesterone, testosterone, vitamin D, cortisol, thyroid hormone)

11

storage role of liver

glucose as glycogen
store cholesterol with TG in liver (esp VLDL)
iron bound to ferritin
B12, ADEK

12

role of bile

breakdown fats
carrier for excretion of bilirubin

13

complication of excess unconjugated bilirubin for several months in newborn

kernicterus: unconjugated bilirubin in brain

chorea
cerebral palsy
hearing loss
gaze abnormalities
brain damage → death

14

neuro effects of excess unconjugated bilirubin in newborn (occur in hrs-days)

bilirubin is neurotoxic:
lethargy
hypotonia

15

prevent kernicterus

phototherapy: convert bilirubin to isomer that can excrete

16

AR mutation in promotor for UDP-glucoronyltransferase gene →↓ amounts of UDP-glucoronyltransferase enzyme
conjugate bilirubin more slowly → slight elevation of INDIRECT bilirubin
benign and asymptomatic unless infection or alcohol (incidental finding)

Gilbert syndrome

17

complete absence of UDP-glucoronyltransferase enzyme
can't conjugate bilirubin and excrete it into the bile
jaundice + ↑ INDIRECT bilirubin in first few days of life
may have NEURO sx
if no treatment: kernicterous (die in a couple years)

type I crigler-najjar syndrome

18

treatment of type 1 crigler-najjar syndrome

phototherapy
plasmaphoresis - remove unconjugated bilribubin bound to albumin
definitive: liver transplant (makes UDP-GT)

19

mutated UDP-glucoronyltransferase enzyme
jaundice + ↑ INDIRECT bilirubin in first few days of life (but less than type I)

type II crigler-najjar syndrome

20

distinguish type I vs type II crigler-najjar syndrome

give phenobarbital (barbiturate): induces liver enzyme production (even UDP-GT)
type II pr Gilbert: ↓ bilirubin
type I: no change (no UDP-GT in liver!)

21

problem putting conjugated bilirubin back into bile → conjugated bilirubin trapped in hepatocytes → turns liver BLACK
↑ DIRECT serum bilirubin
benign - no treatment necessary

dubin-johnson syndrome

22

milder form of dubin-johnson syndrome
mild elevation in DIRECT bilirubin
liver DOESN'T turn black

rotor syndrome

23

stages of alcoholic liver disease

steatosis (fatty liver)
alcoholic hepatitis
alcoholic cirrhosis

24

fat droplets in cytosol of hepatocytes seen in HEAVY drinks
REVERSIBLE if stop drinking

steatosis: fatty liver

25

inflammation + steatosis
swollen necrotic hepatocytes
neutrophils in liver parenchyma
MALLORY bodies: intracytoplasmic eosinophilic inclusions of keratin

alcoholic hepatitis

26

RUQ pain
anorexia
jaundice
low-grade fever
↑AST>ALT (AST >2x the ALT, A Scotch and Tonic = AST)
enlarged, swollen liver

alcoholic hepatitis

27

IRREVERSIBLE
scarring + fibrosis
palpate hard, nodular liver edge
enlarged OR shrunken liver
AST/ALT: may be high, normal, low (trashed liver)
residual nodules of hepatocytse with collagen + sclerosis (blue on trichrome stain) surrounding them (replaced necrotic hepatocytes)
sclerosis located around central vein (zone 3)

alcoholic cirrhosis

28

complications of cirrhosis

liver failure: no hepatocytes
portal HTN: blood can't flow through sinusoids (causes hepatosplenomegaly) → portal vein

29

coagulopathy: ↑PT, PTT (need vitamin K)
bleeding/bruising
↓osmotic pressure → peripheral edema, ascites
no metabolism of ammonia → hepatic encephalopathy (confusion, delerium, hypersomnia, coma, death, asterixis, fetor hepaticus (musty odor of breath)
↑estradiol levels: testicular atrophy, gynecomastia, spider telangiectasia on chest, palmar erythema
↑ unconjugated bilriubin: jaundice, slceral icterus
↓LDL and HDL (liver not making)

liver failure

30

hepatosplenomegaly (blood backs up in these organs, can cause enlarged liver even though cirrhotic)
fluid leaks from liver due to back up of blood → ascites
caput medusa: umbilica veins dilated
anorectal varices: tortuous, dilated vein
esophageal varices (if active bleed → hematemesis, melena)

portal hypertension

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