Usera > Liver 1 Flashcards
(121 cards)
1
Q
what does the portal vein carry?
A
venous blood rich in nutrients from the alimentary tract
2
Q
what does the hepatic artery carry?
A
arterial blood rich in oxygen from the celiac axis
3
Q
what is the blood supply of the liver?
A
- portal vein
2. hepatic artery
4
Q
what veins drain the liver?
A
hepatic veins
5
Q
what vein drains the R lobe?
A
right hepatic vein
6
Q
what does the middle hepatic vein drain?
A
the middle of the L lobe & some of the R lobe
7
Q
what vein drains the left lateral lobe?
A
L hepatic vein
8
Q
what % do the portal vein & hepatic artery contribute to the liver?
A
portal vein = 60-70%
hepatic artery = 30-40%
9
Q
what 3 things make up the portal triad (tract)?
A
portal vein
hepatic artery
bile duct
10
Q
what shape is a liver lobule?
A
hexagonal
11
Q
what is the orientation of a liver lobule?
A
oriented around a hepatic VEIN w/ portal tracts at the periphery
12
Q
define “centrilobular”
A
area of the liver closest to the hepatic vein
13
Q
define “periportal”
A
area of the liver closest to the portal tract
14
Q
which model is used to describe the histopathology of the liver?
A
liver lobule model
15
Q
what shape is a liver acinus?
A
triangular
16
Q
where is the apex of a liver acinus?
A
near the hepatic vein
17
Q
where is the base of a liver acinus?
A
formed by penetrating vessels of portal tract
18
Q
what zone of a liver acinus is closest to the portal tract?
A
zone 1
19
Q
what zone of a liver acinus is closest to the hepatic vein?
A
zone 3
20
Q
which model is used to describe the physiologic relationship of hepatocytes & blood supply of the liver?
A
acinus model
21
Q
the liver is vulnerable to a wide variety of WHAT KINDS of insults?
A
- metabolic
- toxic
- microbial
- circulatory
- neoplastic
22
Q
when do clinical detection & sx of hepatic decompensation occur in liver dz?
A
weeks, months, or many years after the onset of injury
INSIDIOUS ONSET
23
Q
what can confirm the presence of liver dz but not define the CAUSE of liver dz (generally speaking)?
A
biochemical tests that detect abn liver fxn
24
Q
what 3 tests evaluate hepatocyte INTEGRITY?
A
- AST
- ALT
- LDH
25
what 5 tests evaluate biliary excretory fxn?
1. serum bilirubin
2. urine bilirubin
3. alk phos
4. GGT (gamma-glutamyl transpeptidase)
5. 5'-nucleotidase
26
what are the 3 types of serum bilirubin?
1. total
2. direct
3. delta
27
what are the 3 tests that evaluate hepatocyte FXN?
1. albumin
2. ammonia
3. prothrombin time
28
what are the 5 patterns of liver injury?
1. inflammation
2. intracellular
3. necrosis
4. regeneration
5. fibrosis
29
what is the most severe clinical consequence of liver dz?
hepatic failure
30
when do you get hepatic failure?
loss of 80-90% of hepatic fxnal capacity
31
what are the 3 categories of hepatic failure?
1. acute liver failure
2. chronic liver dz
3. hepatic dysfxn w/o overt necrosis
32
what is the most common route with the endpoint of cirrhosis?
chronic liver dz
33
what is the criteria for chronic liver dz?
hepatic necrosis & inflammation present for at least 6 mos
34
what's happening in hepatic dysfxn w/o overt necrosis?
viable hepatocytes w/o the ability to perform metabolic fxns
35
what is fulminant liver failure?
encephalopathy that develops w/i 2 wks of jaundice
36
what is acute liver failure?
liver dz assoc w/ encephalopathy w/i 6 mos after dx
37
what is sub-fulminant liver failure?
encephalopathy that develops w/i 3 MONTHS of jaundice
38
what are the 4 main causes of acute liver failure?
1. drugs
2. toxins
3. infxn
4. autoimmune
39
what drugs can cause acute liver failure?
```
acetaminophen
rifampin
isoniazid
MAOIs
halothane
```
40
what toxins can cause acute liver failure?
carbon tetrachloride
| shrooms
41
what infxns can cause acute liver failure?
hep A
| hep B
42
what are the 7 clinical signs of hepatic dysfxn?
1. jaundice
2. easy bruising (coagulopathy)
3. hypoalbuminemia
4. hyperammonemia
5. hypoglycemia
6. fetor hepatis
7. hyperestrinism
43
what are the 5 sx of hyperestrinism?
1. hypogonadism
2. gynecomastia
3. spider angiomas
4. palmar erythema
5. muscle wasting (shoulder girdle atrophy)
44
how do you get hepatic encephalopathy?
blunt shunting away from the liver > toxic metabolites enter the CNS
45
what is hepatorenal syndrome d/t?
1. poor renal perfusion & renal vasoconstriction (NOT renal pathology!)
2. activated renal sympathetic nervous system d/t vasoconstriction of arterioles
3. synthesis of renal vasoactive mediators
46
what are the sx of hepatorenal syndrome?
1. hyperosmolar urine
2. hyponatremic urine
3. no proteinuria
47
what are the complications of hepatic failure?
1. severe coagulopathy
2. encephalopathy
3. hepatorenal syndrome
4. multiple organ failure
48
what is a complication of portal HTN?
esophageal varices
49
what is hepatic encephalopathy?
disorder of neurotransmission in the CNS & neuromuscular system assoc w/ HIGH AMMONIA
50
what is the spectrum of disturbances of consciousness in hepatic encephalopathy?
subtle behavior diffs to confusion, stupor, coma, & death
51
what are the neurologic signs of hepatic encephalopathy?
rigidity
hyperreflexia
asterixis
52
what is hepatorenal syndrome?
renal failure in pts w/ severe chronic liver dz w/ no intrinsic cause for renal failure
53
what is the common end stage to many underlying liver dzs?
cirrhosis
54
how do you get hypoperfusion in cirrhosis?
fibrosis > vascular disruption > hypoperfusion
55
what type of regeneration do you get w/ cirrhosis?
nodular
56
what kind of disruption is there w/ cirrhosis?
parenchymal/fxnal
57
what is the most common cause of cirrhosis?
alcoholic liver dz
58
what are the 2 RARE causes of cirrhosis?
Wilson dz
| Alpha-1 ATD
59
besides booze, what can cause liver cirrhosis?
1. viral hepatitis
2. biliary dz
3. hemochromatosis
4. Wilson dz (rare)
5. alpha-1 ATD (rare)
6. cryptogenic cirrhosis
60
what 3 things make up "cryptogenic cirrhosis"?
1. NASH
2. autoimmune
3. other
61
what do hepatic stellate cells aka ito cells normally do?
vitamin A storage
62
what happens to hepatic stellate cells aka ito cells in response to inflammatory cytokines or toxin exposure?
they transform into myofibroblasts & deposit collagen 1 & 3
63
T/F: end-stage cirrhosis is non-specific
TRUE
64
what are the 3 morphological characteristics of cirrhosis?
1. bridging fibrosis
2. parenchymal nodule formation
3. architectural distortion
65
what is bridging fibrosis?
deposition of types I & 3 collagen into the space of Disse
66
what facilitates bridging fibrosis?
activation of stellate cells into myofibroblasts
67
what causes bridging fibrosis? (4 things)
1. chronic inflammation
2. cytokine pdtion
3. disruption of the ECM
4. direct stimulation by toxins
68
what is parenchymal nodule formation?
after injury, surviving hepatocytes regenerate as spherical nodules w/i the fibrous septa
69
what does fibrosis do in the context of parenchymal nodule formation?
creates new vascular channels btwn portal vessels & hepatic veins
70
what are the consequences of fibrosis in parenchymal nodule formation?
1. compromises delivery of blood to hepatocytes
| 2. compromises hepatocyte's ability to secrete into plasma
71
why do you get architectural distortion in cirrhosis?
diffuse fibrosis
| diffuse parenchymal injury
72
what is portal HTN?
inc pressure in portal system d/t arterial pressures being imposed on the portal system
73
what are the 3 types of portal HTN?
1. prehepatic
2. intrahepatic
3. posthepatic
74
what are the 3 causes of prehepatic portal HTN?
1. obstructive thrombosis
2. massive splenomegaly
3. portal vein constriction
75
what are the 5 causes of intrahepatic portal HTN?
1. cirrhosis
2. schistosomiasis
3. massive fatty change
4. diffuse granulomatous dz
5. nodular regenerative hyperplasia
76
what are the 3 causes of posthepatic portal HTN?
1. right sided heart failure
2. constrictive pericarditis
3. hepatic vein outflow obstruction
77
what 2 things increase in portal HTN?
1. resistance
| 2. flow
78
where do you get increased resistance in portal HTN?
at the level of the sinusoids
79
what 2 things does increased resistance cause?
1. contraction of vascular smooth muscle cells & fibroblasts
| 2. disruption of blood flow d/t scarring & parenchymal nodule formation
80
why do you get increased flow in portal HTN?
d/t hyperdynamic circulation
81
what does increased flow cause in portal HTN?
arterial vasodilation in the splanchnic circulation which leads to inc venous efflux in the portal system
82
what is ascites?
accumulation of serous fluid in the peritoneal cavity
83
what are 4 things that can give you ascites?
1. sinusoidal HTN
2. hypoalbuminemia
3. thoracic duct overflow
4. splanchnic vasodilation + hyperdynamic circulation
84
what happens d/t the rise in portal system pressure?
blood flow reversal (portal to systemic) d/t dilation of collateral vessels + dvlpmnt of new vessels
85
where are the 4 important porto-systemic shunts (bypasses) important in portal HTN?
1. cardioesophageal jxn
2. rectum
3. retroperitoneum
4. falciform ligament & umbilicus
86
what can happen at the cardioesophageal jxn d/t portal HTN?
esophageal varices, which are prone to rupture
87
what can happen at the rectum d/t portal HTN?
hemorrhoids
88
what can happen at the falciform ligament & umbilicus d/t portal HTN?
caput medusae
89
what is a normal bilirubin level?
0.3-1.2 mg/dL
90
when does bilirubin become clinically evident (how high does it get)?
2-2.5 mg/dL
91
which bilirubin is water soluble: conjugated or un?
conjugated is water soluble
| unconjugated is insoluble
92
which bilirubin is in a TIGHT complex w/ albumin: conjugated or un?
UNconjugated
| conjugated is loosely bound
93
which bilirubin can cause toxic injury: conjugated or un?
UNconjugated can cause toxic injury > kernicterus
| conjugated is non-toxic
94
which bilirubin can be excreted in urine: conjugated or un?
conjugated can be excreted
| unconjugated cannot, even if levels are high
95
what is the physiologic reason for jaundice?
bilirubin pdtion exceeds hepatic clearance
96
T/F: you can get jaundice d/t too much conjugated OR unconjugated bilirubin
TRUE
| although >50% are d/t conjugated
97
what 3 things will give you unconjugated hyperbilirubinemia?
1. overpdtion
2. gilbert's syndrome
3. impaired conjugation
98
what is Gilbert's syndrome?
defective unconjugated bilirubin uptake
99
what are 2 causes of impaired conjugation that can result in unconjugated hyperbilirubinemia?
1. neonatal jaundice
| 2. Criglar-Najjar, types 1 & 2
100
which type of criglar-najjar is auto recessive & severe?
type 1
101
which type of criglar-najjar is autosomal dominant and less severe?
type 2
102
what 2 syndromes can cause conjugated hyperbilirubinemia?
1. rotor syndrome
| 2. dubin-johnson syndrome
103
how is dubin-johnson syndrome inherited?
autosomal recessive
104
what are the 2 types of neonatal jaundice?
1. physiologic jaundice
| 2. breast milk jaundice
105
how does physiologic jaundice work?
mild unconjugated hyperbilirubinemia d/t immature hepatic conjugation & excretion system
106
how does breast milk jaundice work?
there are bilirubin-deconjugating enzymes in breast milk
107
what thing does crigler-najjar involve?
UGT1A1
108
which type of crigler-najjar has ABSENT UGT1A1 activity?
type 1
| type 2 is just decreased
109
T/F: gilbert syndrome is innocuous
true
110
T/F: crigler-najjar type 1 is fatal in the neonatal period
TRUE
111
what is the defect in bilirubin metabolism in dubin-johnson syndrome?
impaired excretion of bilirubin glucuronides d/t mutation in MRP2
112
what is the defect in bilirubin metabolism in rotor syndrome?
decreased hepatic uptake & storage
113
what is cholestasis?
impaired bile formation & bile flow
| leads to accumulation of bile pigment in hepatic parenchyma
114
what 2 things can cause cholestasis?
1. extra or intrahepatic obstruction of bile channels
2. defect in bile secretion
(i. e. biliary obstruction or hepatocyte dysfxn)
115
what are the signs of cholestasis?
1. jaundice
2. pruritis
3. xanthomas
4. silver stool
5. elevated alk phos
6. intestinal malabsorption (vit A, D, K)
116
what is neonatal cholestasis?
prolonged conjugated hyperbilirubinemia
| not a specific entity & not necessarily inflammatory
117
what are the 5 possible causes of neonatal cholestasis?
1. bile duct obstruction
2. neonatal infxn
3. toxic
4. metabolic dz
5. idiopathic neonatal hepatitis
118
what 5 bacterial infxns can cause hepatic failure?
1. extrahepatic (sepsis)
2. Staph aureus
3. Typhoid fever (Salmonella typhi)
4. treponema pallidum (chlamydia)
5. ascending biliary infxn (cholangitis)
119
what 7 parasitic infxns can cause hepatic failure?
1. malaria
2. schistosomiasis
3. strongyloidiasis
4. cryptosporidiosis
5. leishmaniasis
6. echinococcosis
7. liver flukes
120
what are the 3 things listed under parasitic DZ instead of infxn?
echinococcal cyst
clonorchis sinensis
fasciola hepatica
121
name 2 kinds of abscess you can get in your liver
1. bacterial
| 2. amoebic
