Case 5 Flashcards

1
Q

What is the name of the toxic metabolite formed in paracetamol hepatotoxicity?

A

N-acetyl-benzoquinoneimine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is bilirubin conjugated with in the liver, what is formed? (include proportions)

A

80% with glucuronide forming bilirubin glucoronide, 10% with sulfate to form bilirubin sulfate, 10% with other substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the largest visceral organ?

A

The liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The liver is in mostly in which regions?

A

The hypochondrium and epigastric regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two recesses associated with the liver?

A

The subphrenic and hepatorenal recesses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What divides the left and right ares of the subphrenic recess?

A

The falciform ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the falciform ligament derived from?

A

The ventral mesentery in the embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The subphrenic and hepatorenal recesses are continuous where?

A

anteriorly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The liver coated with visceral peritoneum apart from where?

A

The fossa for the gallbladder and the porta hepatis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What attaches the liver to the anterior abdominal wall?

A

the falciform ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What connects the liver to the stomach?

A

the hepatogastric ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What attaches the liver to the duodenum?

A

The hepatoduodenal ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What attaches the liver to the diaphragm?

A

triangular ligaments on the right and left and coronary ligaments on the anterior and posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which of the right lobes of the liver is visable on the anterior of the visceral surface?

A

quadrate lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which of the the right lobes of the liver visible on the posterior of the visceral surface?

A

the caudate lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The quadate lobe of the liver is functionally related to what lobe?

A

The left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What forms the right and left borders of the quadrate lobe of the liver?

A

the fossa for the gall blader on the right and the fissure for the ligamentum teres on the left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What forms the right and left borders of the caudate lobe of the liver?

A

the fissure for the ligamentum venosum of the left and the groove for the vena cava on the right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which two arteries supply the liver? where do they arise from?

A

The right and left hepatic arteries originating from the common hepatic artery from the celiac trunk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does blood drun into after entering the liver the branches of the hepatic portal vein?

A

hepatic sinusoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the name for the specialized macrophages that screen blood entering the liver?

A

Kupffer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the typical size of a liver lobule?

A

1mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

As well as engulfing pathogens and cell debris what is the other function of the kupffer cells of the liver?

A

storage of iron, lipids and some heavy metals such as tin or mercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is glycogenesis?

A

the formation of glycogen from glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is gluconeogensis?

A

the formation of glucose from non carbohydrate sources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is glycogenolysis?

A

the formation of glucose from glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is interconversion?

A

the conversion of one monosacaride to another e.g. glucose to fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is used to synthesize chloesterol int he liver?

A

proteins and carbohydrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the four main things the livershelps to store?

A

glucose, vitamin B12, iron and Vitamin A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What two forms does the liver store iron in?

A

mainly ferritin but also haemosiderin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The liver acts as a reservoir for roughly how much blood?

A

650mls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which type of liver reation is catabolic?

A

phase 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Which phase of liver reaction is anabolic

A

phase 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What type of substance is not well eliminated by the kidneys and so is the target for liver metabolism?

A

lipophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What system does the majority of liver drug metabolism happen in?

A

the cytochrome p450 (CYP) system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Which organelle is most associated with drug metabolising enzymes in the liver?

A

The smooth endoplasmic reticulum

37
Q

What is functionalisation?

A

The addition of a reactive group to a molecule that serves as a point if attack for the conjugating system to attach a substituent

38
Q

How are non-predictable hepatotoxic drugs different from predictable hepatotoxic drugs?

A

Their damage is not associated to their dosage

39
Q

What are the six mechanisms by which a drug can be damaging to a hepatocycte?

A

disruption of calcium homeostasis, disruption of bile canalicular transport mechanisms, formation of non functioning adducts that present on the surface of the cell as new antigens, induction of apoptosis and inhibition of mitochondrial function

40
Q

What is the toxic dose of paracetamol?

A

10-15g

41
Q

How does inhibition of mitochondria damage hepatocytes?

A

it prevents fatty acid metabolism and causes accumulation of lactate and reactive oxygen species

42
Q

What is haemoglobin first converted to when it enters a macrophage?

A

the haemoglobin is split into haem and globin

43
Q

What happens to globin one it is separated from haemoglobin in macrophages?

A

it is broken down into its constituent amino acids and used to synthesis other proteins

44
Q

What happen to the Fe3+ when it is removed from a haeme group in a macrophage?

A

it attaches to the iron storage protein transferrin

45
Q

What happens to the iron stored in transferrin in muscle fibres liver ells and macrophages of the spleen and liver?

A

It dissociates from transferrin and instead becomes associated with ferritin

46
Q

What happens to the haem group in haemoglobin one it is detached from globin and iron?

A

It is converted to biliverdin then quickly to unconjugated bilirubin

47
Q

What is unconjugated bilirubin transported by in the blood on its way to the liver?

A

plasma albumin

48
Q

What proportion of bilirubin entering the liver is conjugated with glucoronic acid? What is formed?

A

80% it forms bilirubin glucuronide

49
Q

What proportion of bilirubin entering the liver is conjugated with sulfate? what is formed?

A

10% it forms bilirubin sulfate

50
Q

What highly soluble compound is bilirubin converted to in the large intestine? What proportion of bilirubin is converted?

A

about half is converted forming urobillinogen

51
Q

What happens to urobillogen once it enters urine?

A

it is oxidised forming urobilin

52
Q

What is the van den Bergh reaction? What two conditions does it help distinguish between? why does it distinguish between these two?

A

A reaction that can reveal whether the majority of bilirubin in the blood is conjugated or not this shows whether jaundice is haemolytic or obstructive as in haemolytic blood bilirubin is raised due to it being released from damaged erythrocytes whereas in obstructive it is raised due to conjugated bilirubin being released into the blood as it cannot be released into the GI tract

53
Q

What are the three main types of jaundice?

A

prehepatic, hepatic and post hepatic

54
Q

What are the two most common causes of hepatic jaundice

A

viral hepatitis and cirrhosis

55
Q

The presence of Aminiotranferase in the blood indicates what?

A

hepatocyte necrosis

56
Q

What is chloestasis?

A

the inability of bile to flow away from the liver

57
Q

Which hepatotropic viruses use RNA as their nucleic acid?

A

A, C and E

58
Q

Which hepatotropic viruses are oncogenes?

A

B, C and D

59
Q

What is the incubation period of hepatitis A?

A

3-6 weeks

60
Q

What is the most common form of viral hepatitis?

A

Hepatitis A

61
Q

What is released into the blood upon the on set of symptoms in Hep A?

A

IgM anti HVA antibody

62
Q

What type of food can cause an infection of HVA?

A

raw shellfish

63
Q

What is the primary transmission route for hepatitis A?

A

faecal oral

64
Q

Where is the hepatitis A virus common?

A

the indian subcontinent, africa, central and southern america and far & eastern europe.

65
Q

What is the second most common cause of viral hepatitis?

A

Hepatitis B

66
Q

What are the five possible outcomes of Hepatitis B infection?

A

Acute hepatitis with recovery and clearance of the virus, non progressive chronic hepatitis, progressive chronic disease ending in cirrhosis, fulminant hepatitis will massive liver necrosis and an asymptomatic carrier state.

67
Q

In areas of endemic Hepatitis B what are the most common modes of transmission?

A

From mother to child and exposure to infected blood (especially from one infected child to an infected child under 5)

68
Q

In areas of low endemicity what are the two most common modes of transmission of Hepatitis B

A

Use of contaminated needles for drug use and sexual transmission

69
Q

What is the incubation period of hapatitis B

A

on average 75 fdays but it can vary from 30-180 days

70
Q

What are the two phases of a chronic HBV infection

A

replicative and integrated

71
Q

In what phase of a chronic infection of HBV is there active viral replication with hepatic inflammation, where the patient with be highly contagious and would have high levels of blood antigen

A

replicative

72
Q

What is the mode of action of Peginterferon alpha 2a?

A

It binds to type 1 interferon receptors which upon dimerisation activate two Jak tyrosine kinases these transphosphorylate each other and their receptors. The phosphorylated receptors then bind to Stat1 and Stat2 which dimerise and activate multiple.

73
Q

What is the incubation period of Hepatitis C?

A

7-8 weeks

74
Q

What is unique about hepatitis C infection?

A

it is often asymptomatic however often causes scarring of the liver and ultimately cirrhosis

75
Q

What is unique about hepatitis D infection?

A

it can only occur if a person is already is infected with hepatitis B

76
Q

What is the other name for liver failure caused by hepatitis?

A

Fulminant hepatitis.

77
Q

What is unique about hepatitis G?

A

It appears to replicate in bone marrow and the spleen

78
Q

What are the main two routes of transmission for hepatitis G?

A

Exposure to contaminated blood and sexual contact

79
Q

How is chronic hepatitis defined?

A

inflammatory disease of the liver lasting more than 6 months

80
Q

What apart from hepatitis viruses can cause chronic hepatitis?

A

Epstein-barr virus, metabolic conditons, toxic and drug causes, autoimmuno conditions and sarcoidosis

81
Q

What are the three central pathogenic processes in cirrhosis?

A

ecm deposition, death of hepatocytes and vascular reorganisation

82
Q

What is the primary mechanism of fibrosis is cirrhosis?

A

proliferation of hepatic stellate cells that activate to become myofibrogenic cells that are highly fibrogenic collagen forming cells

83
Q

What is released from stellate cells in their early stages of activation?

A

retinoids

84
Q

What is the difference between micronodular and macronodular cirrhosis?

A

Micronodular cirrhosis has regenerating nodules of less than 3mm and effects the whole liver uniformly and is often caused by ongoing alcohol damage, macronodular cirrhosis has variable nodule size and is often seen following viral hepatitis

85
Q

What is hepatorenal syndrome?

A

The deterioration of kidney function in individuals with cirrhosis or fulminant liver failure

86
Q

What are the three main complications associated with hepatic failure?

A

Hepatic encephalopathy, hepatorenal syndrome and hepatopulmonary syndrome

87
Q

What chemical is thought to be responsible for the majority of the effects of hepatic encephalopathy what does it cause?

A

ammonia is thought to be responsible and causes impaired neural function and generalized brain oedema

88
Q

What usual heralds hepatorenal syndrome?

A

drop in urine output with rising blood urea nitrogen and creatinine.

89
Q

What is the triad that heralds hepatopulmonary syndrome

A

chronic liver disease, hypoxemia and intra-pulmonary vascular dilations