Cell Injury

Question 1

what is steatosis? how does it occur?

Answer 1

fatty change in the liver; alcohol changes fat metabolism by decreasing fatty acid oxidation, decreasing lipoprotein synthesis and increasing triglyceride synthesis.

Question 2

What is Mallory’s hyaline?

Answer 2

an example of permanent damage to a hepatocyte. abstinence from alcohol will still leave a damaged hepatocyte. dense pink rope like body in the cytoplasm of hepatocytes and is an accumulation of Cytokeratin filaments.

Question 3

what is hemochromatosis?

Answer 3

a genetic disease that results in abnormal accumulation of iron in tissues. seen as rusty tan color in stain.

Question 4

Burkitt lymphoma is an example of:

what histological pattern is associated with this:

Answer 4

macrophage phagocytosis of apoptotic B cells
“starry sky” – lightly stained macrophages with apoptotic bodies surrounded by the dense infiltrate of malignant lymphocytes

Question 5

what is ischemia?

Answer 5

the effect of oxygen deprivation on cell morphology

Question 6

what are some of the early, reversible effects of hypoxia on a cell?
a histologic example of early hypoxia would be:

Answer 6

increased cell volume as Na enters w/water, increased Ca influx causes damage to cell membrane
myocardial edema

Question 7

what is necrosis?

Answer 7

cell death at tissue level.&raquo_space; morphological changes of tissue due to enzymatic degradation of dead cells by lysosomal enzymes, and denaturation of proteins

Question 8

The two types of necrosis are _____ and _____

Answer 8

coagulative and liquifactive

Question 9

Coagulative necrosis results from:

Answer 9

denaturation of proteins (dominate picture). ex: mycoardial/renal/pulmonary infarction

Question 10

Liquifactive necrosis results from:

Answer 10

extensive inflammation due to bacteria or fungus&raquo_space; complete digestion of tissue. ex: abcess & cerebral infarction

Question 11

what is caseous necrosis?

Answer 11

usually associated w/TB. combo of liquifactive and coagulative necrosis&raquo_space; cheese like morphology

Question 12

1) Distinguish reversible from irreversible cell injury.

Answer 12

reversible ex: steatosis. Liver hepatocyte–> steatosis (fatty change)&raquo_space; abstinence&raquo_space;healthy hepatocyte
permanent: ex: hepatocyte –> mallory’s hyaline (cytokeratin) –> abstinence –> damaged hepatocyte
reversible ex2: excess iron absorption&raquo_space; hemosiderosis&raquo_space; treatment&raquo_space; normal hepatocyte
permant ex 2: hemosiderosis&raquo_space; no treatment&raquo_space; cirrhosis

Question 13

2) Identify the cytological changes that are associated with irreversible injury.

Answer 13

Mitochondrial swelling, loss of nuclear envelope/cell membrane, invasion by keratin filaments

Question 14

3) Explain how steatosis occurs due to alcohol ingestion.

Answer 14

Mobilizization of fatty acids from stores
Decreased fatty acid oxidation
Increased triglyceride synthesis
Increased lipoprotein synthesis
Decreased glycosylation & transport of VLDL = accumulation of tryglycerides in liver

Question 15

4) Name and distinguish 4 types of pathological necrosis.

Answer 15

Liquifactive: necrosis w/significant inflammation often due to bacterial or fungal infection. ex: abcess or cerebral infarction
Coagulative: most common. denaturation of cellular proteins. ex: ischemic origin, “white necrosis”
Caseous: combo of L & C necrosis
Gangrenous: overlay of liquifactive on already necrosed tissue

Question 16

5) Explain the relationship between hemochromatosis and cirrhosis.

Answer 16

Hemochromatosis (genetic increase in iron absorption) results in liver cirrhosis if untreated. Overaccumulation of iron&raquo_space; scarring (cirrhosis)

Question 17

6) Diagram the mechanisms active in cellular apoptosis.

Answer 17

1

Question 18

7) Name four features of cellular injury that are reversible.

Answer 18

cellular swelling
loss of microvilli
Bleb
myelin figures
ER swelling

Question 19

8) Describe the electrolyte shifts that occur in ischemic cell injury leading to cell death.

Answer 19

Cells lose ability to maintain Na/K gradient via ATPase (no O2 = no oxidative phosphorylation). Na and Ca enter the cell and result in additional injury to cytoskeletal and membrane integrity

Question 20

9) Explain the role of Ca++ ions in irreversible cell injury.

Answer 20

Enters cell freely and causes release of phospholipases, proteases, endonucleases, and decreased ATPase activity. Mitochondria swell and Ca deposits are seen on EM.