Microscopic anatomy of liver disease

Question 1

The image below shows normal liver microanatomy. What do each of the numbers labelled relate to?

Answer 1

1 - hepatocytes

2 - bile canaliculi

3 - bile duct

4 - branch of hepatic vein

5 - portal triad

6 - hepatic artery

7 - sinusoids

8 - central vein

Question 2

What are the sinusoids of the liver?

Answer 2

• vascular spaces between hepatic plates
• blood flows from portal triad to central vein

Question 3

What are the bile cannaliculi of the liver?

Answer 3

• sit between hepatocyes as these produce bile
• bile oves from central vein to portal triad

Question 4

What are hepatic nodules?

Answer 4

• hexagon shapes of liver organisation
• central vein is in the middle

Question 5

Acinar zones 1,2,3 are zones within the hepatic lodules. What is the relevence of the acinar zones?

Answer 5

• receiving blood progressively poorer in oxygen and nutrients close to central vein
• zone 3 will recieve blood that has been extracted of O₂ and nutrients from zones 1 and 2

Question 6

Acinar zones 1,2,3 are zones within the hepatic lodules. The acinar zones receive blood progressively poorer in oxygen and nutrients close to central vein. For example, zone 3 will recieve blood that has been extracted of O2 and nutrients from zones 1 and 2. Out of the 3 zones which is likley to suffer from ischemia and become damaged?

Answer 6

• zone 3

Question 7

In the liver histology section image below, what do the colour arrows depict?

Answer 7

• red = hepatic artery
• green = bile duct
• blue = portal bein

Question 8

In the liver histology section image below, what do the darker spots around the sinusoids depict?

Answer 8

• inflammatory cells

Question 9

What is the space of Disse?

Answer 9

• a location in the liver between a hepatocyte and a sinusoid
• contains blood plasma
• can only been seen in pathophysiology

Question 10

The sinusoidals of the liver are lined by a specific type or endothelial cell, what is this cell and what is the importance of this?

Answer 10

• fenestrated (like a sink hole with little holes)
• allows transfer of nutrients and plasma between hepatocytes and blood vessels

Question 11

What are the immune cells of the liver?

Answer 11

• kupffer cells (macrophages)

Question 12

Stellate cells of the liver, sit in the space of disse and are important for storage. What do they store?

Answer 12

• vitamin A

Question 13

Hepatocytes contain a fine granuler eosinophilic cytoplasm. What colour does this stain on H&E staining?

Answer 13

• protein stain pink
• nucleus stains blue

Question 14

Do hepatocytes contain glycogen?

Answer 14

• yes and can be stained for
• important for energy and blood glucose of liver

Question 15

The image below is H&E stain of hepatocytes. What do the numbers 1, 2 and 3 denote?

Answer 15

1 - sinusoids

2 - nuclei of hepaticytes

3 - kupffer cells

Question 16

In addition to storing and metabolising vitamin A, what else do stellate cells do?

Answer 16

• play a leading role in fibrogenesis
• cells transform into myofibroblasts that can lay down collagen
• reticulin fibers lay down collagen III, fibrous collagen can cause liver dysfunction

Question 17

What is the white space in the image below of hepatocytes?

Answer 17

• central vein

Question 18

In the image of the bilary tree below, what do the numbers 1-8 denote?

Answer 18

1 - right hepatic duct

2 - cystic duct

3 - gall bladder

4 - ampulla

5 - pancreatic duct

6 - bile duct

7 - common hepatic duct

8 - left hepatic duct

Question 19

What cells line the bilary tree intrahepatically?

Answer 19

• cholangiocytes
• intrahepatic has small ducts and large ducts
• small = portal tracts (columnar) and surface epithelium (cuboidal)
• large ducts = surface epithelium surrounded by fibrous duct wall (columnar)

Question 20

What cells line the bilary tree extrahepatically?

Answer 20

• cholangiocytes
• all columnar surface epithelium surrounded by fibrous duct wall
• contain a Muscle layer but not well defined until distal common bile duct (lower 1/3 of extrahepatic bile duct)

Question 21

In ALD and NAFLD where does fat accumulate?

Answer 21

• in the cytoplasm of hepatocytes

Question 22

The fat that gathers in the cytoplasm of hepatocytes in ALD and NAFLD can be classed as Macro and Microvesicular steatosis, what does this mean?

Answer 22

• macrovesicular steatosis = fat vacuoles larger than the nucleus, displace nucleus
• microvesicular steatosis = fat vacuoles smaller than the nucleus and mostly a foamy appearance with central nucleus

Question 23

To confirm a diagnosis of steatosis, what other changes are needed to be classified as steatohepatitis?

Answer 23

• hepatocellular ballooning degeneration.
• mallory-denk bodies (intermediate cytoskeleton)
• necroinflammation
• fibrosis

Question 24

What causes a hepatocyte to balloon?

Answer 24

• hepatocytes are filled with fat
• cells are unable to regulate the cell size
• cytoskeleton, specifically intermediate filaments then clump together

Question 25

When hepatocytes balloon, why do they appear clear?

Answer 25

- cytoskeleton is not able to maintain cells and so collapses

Question 26

In normal liver tissue there should be no gaps between hepatocytes, except for at the sinusoidals. However, in the image below of H&E staining there are empty spaces. What does this image show, identified by the arrows?

Answer 26

- spaces where inflammatory cells have destroyed hepatocytes - neutrophils are present - this is called necroinflammation

Question 27

The liver should have no collagen in the parenchyme, howeverm in inflammation, what is parenchyme tissue replaced with?

Answer 27

- collagen and fibrosis - called chicken wire fibrosis - liver cells are yellow and fibrosis is red

Question 28

In NADLD, where can be reveressed?

Answer 28

- liver fibrosis

Question 29

In NADLD, once a patient has fibrosis and cirrhosis, what is the risk of increased?

Answer 29

- hepatocarcinoma - liver cancer

Question 30

What does cirrhosis refer to in liver disease?

Answer 30

- yellow nodules form on the liver - end stage diffuse scarring process - nodularity can be macronodular or micronodular (depends on the size)