1. Liver Structure, Function and Dysfunction

Question 1

What things can cause damage to the liver?

Answer 1

Alcohol
Fatty liver disease
Viruses
Drugs
Autoimmune
Inherited metabolic syndromes
Vascular
Chronic biliary disease

Question 2

How heavy is the average liver?

Answer 2

1.5kg

Question 3

How regenerative are hepatocytes?

Answer 3

Stable cells

Question 4

What is the blood supply to the liver?

Answer 4

Hepatic artery and portal vein

Question 5

What are sinusoids lined with?

Answer 5

Fenestrated epithelium and Kupffer cells

Question 6

What is the space between sinusoids and hepatocytes known as?

Answer 6

Space of Disse

Question 7

What type of cell is found in the Space of Disse?

Answer 7

Hepatic Stellate Cells

Question 8

What is the function of hepatic stellate cells?

Answer 8

Can transform into myofibroblasts if the liver is injured, and can both lay down and digest collagen

Question 9

What is the venous drainage of the liver?

Answer 9

Hepatic vein
IVC
Right ventricle

Question 10

What is a portal tract made up of?

Answer 10

Portal vein
Hepatic artery
Bile duct

Question 11

What cell produces bile?

Answer 11

Hepatocytes

Question 12

Give the drainage of bile

Answer 12

Cannaliculi between hepatocytes
Small ductules
Small ducts in portal tracts
Left and right hepatic duct join to form common hepatic duct
CHD + cystic duct = common bile duct

Question 13

What are the causes of vascular injury to the liver?

Answer 13

Venous congestion
Obstruction to venous outflow
Ischaemic injury

Question 14

What is Budd Chiari syndrome?

Answer 14

Thrombus in venous outflow, associated with polycythaemia

Question 15

What length of time defines chronic liver damage?

Answer 15

> 6 months

Question 16

What kind of necrosis is seen in small groups of cells?

Answer 16

Spotty necrosis

Question 17

What kind of necrosis is seen in large groups of cells?

Answer 17

Bridging necrosis

Question 18

What is the grade in relation to liver damage?

Answer 18

The extent of inflammation and necrosis

Question 19

What is piecemeal necrosis?

Answer 19

Inflammation is both portal and lobular

Question 20

What is the stage in relation to liver damage?

Answer 20

How much fibrosis is present

Question 21

What are the 2 reasons a slide of a liver might be blue

Answer 21

Trichrome stain: collagen

speckly blue= iron= haemochromatosis

Question 22

What is cirrhosis?

Answer 22

Diffuse distortion of liver architecture
Fibrous bands surround regenerative nodules
Vascular relationships are distorted

Question 23

What vascular changes take place in cirrhosis?

Answer 23

Obliteration/thrombosis of veins
Shunts form
Sinusoids become capillarised
Increased hepatic venous pressure gradient

Question 24

What does it mean for sinusoids to become capillarised?

Answer 24

They lose their fenestrations

Question 25

What initiates portal hypertension?

Answer 25

Increased pressure gradient

Question 26

What augments portal hypertension?

Answer 26

Splanchnic vasodilation, which increases portal blood flow

Question 27

What is hyperdynamic circulation?

Answer 27

Splanchnic vasodilation means the rest of the body is getting less blood, so the body compensates to increase CO

Question 28

What compensation mechanisms are seen in portal hypertension?

Answer 28

RAAS and ADH which increase Na and water retention | Reflex renal vasoconstriction

Question 29

What are the effects of reflex renal vasoconstriction?

Answer 29

Reduce renal perfusion and GFR | Causes hepatorenal syndrome

Question 30

What causes acites?

Answer 30

Sodium and water retention | Low albumin due to dysfunctional liver causes leakage from peritoneal vessels

Question 31

What are shunts?

Answer 31

Fluid tries to find a way around the high pressure in the portal system Both intrahepatic and extrahepatic

Question 32

What are the effects of shunts?

Answer 32

Blood bypasses the liver, reducing perfusion and function | porto-systemic anastamoses dilation

Question 33

What is the difference between compensated and decompensated cirrhosis?

Answer 33

Compensated is a potentially unstable state without symptoms

Question 34

What are the symptoms of decompensated cirrhosis?

Answer 34

``` Ascites Hepatic encephalopathy Variceal haemorrhage Hepatorenal syndrome Jaundice Infection Hepatocellular carcinoma ```