Chapter 18: Liver Flashcards
(264 cards)
- Which 3 serum enzyme measurements represent a response to disrupted hepatocyte integrity?
- Aspartate aminotransferase (AST)
- Alanine aminotransferase (ALT)
- Lactate dehydrogenase (LDH)
- ___________ measure the biliary excretory function.
- Serum bilirubin
- Urine bilirubin
- Serum bile acids
- Serum measurements of which 2 enzymes look for damage to bile canaliculus?
- Serum alkaline phosphatase (ALP)
- Serum gamma-glutamyl transpeptidase (GGT)
- What are the tests that look for hepatocyte synthetic function (synthethesis)?
- Serum albumin
- Coagulation factors: PT, PTT, fibrinogen, prothrombin, factors V, VII, IX, and X
- Hepatocyte metabolism:
- serum ammonia (↑ in L.D)
- aminopyrine breath test (hepatic demethylation): (↓ in L.D)
As liver function decreases = coag levels ______ = PT levels _____
- decrease
- increase
Alcoholic liver disease:
↑ ____ > ↑ ____
↑ AST > ↑ ALT (2:1)
Most types of hepatitis that damages hepatocytes
↑ ____ > ↑ ____
↑ ALT > ↑ AST
Alkaline Phosphotase (ALP) is a __________ that measures _________.
Enzyme from liver, bones and GI tract;
- ↑ when bile flow is obstructed (cholestasis) =
- can also rise in pregnancy (placenta); thyroid disease and bone disease
To determine if an ↑ in ALP is due to liver, biliary tree or bones, we measure _____.
GGT = ↑ in cholestasis and biliary obstruction, does not rise in bone disease.
- ↑ ALP & ↑ GGT = ______ cause.
- ↑ ALP & NL GGT = ____ cause.
- Hepatobiliary
- Bones
- 2 reversible changes in hepatocytes (2)
- Steatosis: accumulation of fat in the liver
- Cholestasis: accumulation of bilirubin in the liver
When injury is not reversible, hepatocytes die via ______ or ______.
- Necrosis
- Apoptosis
_________ is the predominant mode of hepatocyte death seen in ischemic/hypoxic injury and responses to oxidative stress. Describe this mechanism.
Necrosis;
- Defect in osmotic resgulation causes fluid to enter the cell => cell swells and ruptures (lysis)
- MO accumulate at sites of necrosis
____________ is the type of cell death seen in acute and chronic hepatitis. Describe the process.
Apoptosis.
- Hepatocyte shrink
- Chromatin condenses (pyknosis)
- Fragmentation (karyorrhexis)
- Cellular fragmentation into acidophilic apoptotic bodies (adidophil bodies)
________ increase at sites of hepatocyte injury and mark sites of hepatocyte necrosis.
MO
Councilman bodies are the apoptotic bodies associated with what disease?
Yellow Fever
When there is widespread parenchymal loss, there is often evidence of ___________.
When does this occur?
Confluent necrosis; severe zonal loss of hepatocytes.
- Begins as a zone of hepatocyte dropout around the central vein.
- Produce a space filled with cellular debris, MO, and remnants of the reticular meshwork
Occurs in: acute toxic injury, ischemic injury, viral/AI hepatitis.
What is bridging necrosis?
What disease do we see this in?
- Vascular insult (inflammation or thrombosis) causes zonal loss of hepatocytes to occur in between [central veins - portal tracts; portal tract - portal tract] => parenchymal extinction and collapse of the supporting network.
- Cirrhosis
Regeneration of the liver occurs via 2 major mechanims, which are?
What is the predominant method?
1) Proliferation of hepatocytes adjacent to those that have died ***
2) Stem cell replenishmenemt
Is stem cell replenishment a big part of parenchymal repair when hepatocytes are regenerating?
- NO
- However, hepatocytes are almost stem-cell like; they can continue to replicate even in the setting of years of chronic injury.
When do stem cells begin to contribute significantly to restoring the liver parenchyma?
In chronic diseases via ductal reactions (heptocytes reach replicative senescence => + of stem cells => form ductular reactions => restore parenchyma).
__________ is the main type of liver cell involved in scar deposition => cirrhosis.
Stellate cell.
- NL: stellate cells are dormant and store lipids (vitamin A).
- However, when there it acute or chronic injury, they becomes fibrogenic myofibroblasts => secrete TGF-B and initiate fibrosis.
Describe the process of activation of stellate cell from a lipid-storing cell => fibrogenic myofibroblast => fibrosis.
-
-
Kupffer cells are + => release mutuple cytokines:
1. PDGF-B and TNF (others: TGF-B, MMP-2 and TIMP-1/2) => proliferation and (+) stellate cells (lipid-storing => myofibroblasts).
2. Stellate cells transform into myofibroblasts that contract when stimulated by ET-1 (endothelin-1)
3. Chemotaxis of + stellate cells to areas of injury are promoted by PDGF and MCP-1 (Monocyte chemotactic protein-1.
- Stellate cells begin to secrete TGF-B => produce collagen and initate fibrosis.
-
Kupffer cells are + => release mutuple cytokines:
What stimulates (+) of stellate cells & scar formation?
- Chronic inflammation, with production of inflammatory cytokines (TNF, IL-1B and lymphotoxin)
- Cytokines and chemokines made from Kupffer cells, endothelial cells, hepatocytes and bile duct epithelial cells
- Disruption of ECM
- Direct stimulation by toxins
If injury persists => scar deposition begins, often in the Space of Disse .


















