Cell Injury Flashcards
necrosis is ___ injury
unselective
irreversible
apoptosis is ___ injury
selective
irreversible
hepatic lipidosis is ___ injury
reversible
what are the 4 main categories of cell injury causes?
deficiency of critical material
lack of cellular energy production
accumulation of abnormal substances
physical injury
List the reversible and irreversible ischemic cell injury
reversible - mitochondrial damage
irreversible - membrane damage
define ischemia
inadequate blood supply to an organ or part of body
list the physical signs of reversible cell injury
cell swell
ER swell
loss of microvilli
membrane blebs
clumped chromatin
lipid accumulation
myelin figures
list the physical signs of irreversible cell injury
cell membrane damage, rupture
list the physical signs of cell death
pyknosis
karyorrhexis
karyolysis
absence of nuclei
cytoplasmic eosinophilia
describe the pathogenesis of cell injury due to oxygen deprivation
hypoxia > aerobic cell metabolism stops (decreased oxidative phosphorylation) > decreased ATP production
describe pathogenesis if no oxygen appears to reverse the hypoxic injury due to oxygen deprivation
switch to anaerobic metabolism > intracellular acidosis > lose ribosomes due to swollen ER > cell membrane defects, lysosome rupture > release RNA/DNA > membrane rupture > cell death and rupture
what happens if there’s a LARGE number of cell deaths?
gap is replaced with fibrous CT
what pathology is shown in this image?
renal infarct
define infarct
small area of dead tissue due to failure of blood supply
define hydropic degeneration
reversible or irreversible?
water movement into cells (swelling)
reversible
describe the pathogenesis of hydropic degeneration
injury(hypoxia) > mitochondria activity decreased > cell membrane damaged > interfered ion channels of membranes > NaK ion pump equilibrium dec > Na level increase in cytoplasm > H20 accumulated > mitochondria and ER swelling > hydropic degeneration
what type of hydropic degeneration is caused by parapoxvirus?
Ballooning degeneration
what type of cell injury is caused in this image of muscoa?
Hydropic degneration
what is this an example of in the mucosa of a cow tongue? (black circles and arrow)
circles - ballooning degeneration
arrow - viral inclusion bodies
define hepatic lipidosis
“fatty change”
intracellular accumulation of fatty acids within cytoplasm of hepatocytes
what are the possible mechanisms that can result in lipid accumulation?
- excessive delivery of FFA from fat stores or diet
- dec oxidation or use of FFA
- impaired synthesis of apoprotein
- impaired combination of protein and triglycerides to form lipoproteins
- impaired release of lipoproteins from hepatocytes
just one step needs to go wrong for hepatic lipidosis
what cell injury does this liver have?
hepatic lipidosis
note nucleus pushed to side unlike hydropic degeneration
what organ is this? describe the abnormality
liver
pale/yellow, swollen, friable, greasy
what diseases are associated with lipid accumulation in the liver?
-ketosis and pregnancy toxemia
-inappetence and anorexia
-high fat diets and obesity, hepatotoxins, hypoxia, DM, and hypothyroidism
difference between gross texture/color of lipid vs glycogen hepatocyte accumulation
lipid - pale yellow, friable
glycogen - pale tan/white, firm
list some disorders associated with lipid hepatocyte accumulation
ketosis
pregnancy toxemia
high fat diet
obesity
hepatotoxins
hypoxia
diabetes mellitus
hypothyroidism
list some disorders associated with glycogen hepatocyte accumulation
excess glucocorticoids
diabetes mellitus
young animals
describe positioning of nuclei in lipid hepatocyte accumulation histology
nuclei pushed to periphery
describe vacuole shape/border in lipid hepatocyyte accumulation
distinct borders
describe positioning of nuclei in glycogen hepatocyte accumulation histology
nuclei stay central
describe vacuole shape/border in glycogen hepatocyte accumulation
margins are irregular or indistinct
ID what is accumulated in the section circled of the liver
glycogen
what pathology is shown in this liver?
glycogen accumulation - hepatocellular vacuolation
ID what is accumulated in each liver section
left - fat
right - glycogen
what disease is shown in this image of a dog brain?
lysosomal storage disease
lysosome can’t digest proteins
define pyknosis
irreversible condensation of chromatin in nucleus of cell
define karyorrhexis
fragmentation of nucleus
define karyolysis
nucleus is pale, dissolution of nucleus
when is the nucleus absent in cellular necrosis
later stage of karyolysis
Name the cell stage of cellular necrosis and describe the nucleus
Match each number to its terms
terms - pyknosis, karyorrhexis, and karyolysis
1 - pyknosis
2 - karyorrhexis
3 - karyolysis
which of the following describes necrosis and which describes apoptosis?
Describe the pathogenesis of mitochondrial (intrinsic) apoptosis
cell injury > BCL2 family sensors > BCL2 family effectors (BAX, BAK) > mitochondria > cytochrome C > initiator caspase-9 > executioner capases > endonuclease activation/breakdown of cytoskeleton > cytoplasmic bleb > apoptotic body > phagocyte ingests apoptotic body
Describe the pathogenesis of the death receptor (extrinsic) pathway
receptor-ligand interaction > adaptor proteins > initiator caspase-8 > executioner capases > endonuclease activation/breakdown of cytoskeleton > cytoplasmic bleb > apoptotic body > phagocyte ingests apoptotic body
what are the pro-apoptotic of BCL2 family effectors?
BAX, BAK
what are the executioner capases?
capases 3,6,7,12
Is this necrosis or apoptosis? How can you tell?
apoptosis
fragmented cell and no inflammation
cell shrinkage, chromatic condensation
What does increased eosinophilia indicate? what does it look like?
necrosis - RNA degrading
looks pink/red
what are the anti-apoptotic of BCL2 family?
BCL2, BCL-XL
what are the key morphologic features of necrosis on HE stain?
increased eosinophilia, glassy appearance, cytoplasmic vacuolation, karyolysis, ghost cells
what is the red indicating on the image? what is the arrow showing (within the nucleus)?
red - hypereosinophilia
arrow - viral inclusion body
Given the right image is normal what is happening on the left image?
necrosis
define coagulative necrosis
denaturation with dense/rigid texture to dead cells
maintains shape
define liquefactive necrosis
process of complete enzymatic digestion of cells, usually in brain, squishy
define caseous necrosis
cheesy, coagulative, granulomatous reaction
define fat necrosis
saponification
fatty acids mixed with calcium, chalky white
define gangrenous necrosis
necrosis due to ischemia of distal extremities
what type of necrosis is this?
coagulative
maintains shape, myofibers fragmented, nuclei lost
what type of necrosis is this?
coagulative necrosis, renal papillary necrosis
what is the pathogenesis of renal papillary necrosis?
inhibition of prostaglandin synthesis by NSAIDs by inhibition of COX1 and COX2 > predisposes kidney to renal hypoperfusion > ischemia > papillary necrosis
prostaglandins are primary vasodilators in kidney
what type of necrosis is this?
suppurative necrosis - type of liquefactive necrosis
Define infaraction
obstruction of blood supply to organ or tissue causing local death of tissue
what type of necrosis is this?
Liquefactive necrosis
what type of necrosis is this?
Caseous necrosis
which two types of necrosis is caseous necrosis a combination of?
coagulative and liquefactive
what type of necrosis is this?
fat necrosis
what type of necrosis is this?
gangrene/gangrenous necrosis
what is wet gangrene?
combination of coagulative necrosis from loss of blood supply with a liquefactive component due to superimposed infection
