Cell Death Flashcards
what are the three types of severe nuclear changes associated with cellular death?
pyknosis
karyorrhexis
karyolysis
what is pyknosis?
severe condensation of chromatin
basophilia
what is karyorrhexis?
nuclear fragmentation of pyknotic nucleus
what is karyolysis?
nuclear dissolution
swollen
what are the six parts of irreversible injury?
increased cell swelling
disruption lysosomes
breaking of membranes (mitochondria and cellular)
detachments of ribosomes from rER
cytoplasmic blebs
severe nuclear changes
what are key parts of a cell moving from injury to irreversible?
ischemia
disruption intracellular calcium
switch to glycolysis
are there histologic changes with acute cell death?
not necessarily
what are the cytoplasmic changes associated with necrosis?
swelling
fragmentation
hypereosinophilia
what do necrotic cells do histologically?
increased eosinophilia in cytoplasm
lose adherence with adjacent cells
can calcify
what happens in coagulative necrosis?
denaturation of proteins
cellular architecture retained
what is coagulative necrosis usually due to (physiologic states)?
hypoxia
ischemia
acute toxicity
what is the gross appearance of coagulative necrosis?
pale tan-gray, sharply demarcated, solid
what happens in liquefactive necrosis?
necrotic debris converted into fluid phase- no tissue architecture
loss gross or histologic tissue architecture
what type of necrosis is typical of focal bacterial or fungal infections?
liquefactive necrosis
what type(s) of necrosis occur in the CNS?
liquefactive only
what is caseous necrosis typical of?
Mycobacterium tuberculosis/bovis or related bacteria
what is the necrotic debris of caseous necrosis composed of?
dead white blood cells, poorly degraded lipids
true/false: caseous necrosis is often walled off with a ring of fibrous tissue and/or macrophages
true
what are the types of fat necrosis?
pancreatic
nutritional
traumatic
idiopathic
what are the two types of gangrenous necrosis?
dry and wet
what is dry gangrenous necrosis?
coagulation necrosis and mummification
extremities
what is wet gangrenous necrosis from?
invasion/putrefaction of necrotic tissue from saprophytic bacteria
where does wet gangrenous necrosis develop?
tissues that retain moisture and warmth
where is fibrinoid necrosis seen?
vascular walls
what are the possible causes of fibrinoid necrosis?
infectious
noninfectious (immune mediated…)
shock
what happens to the plasma membrane in apoptosis?
it remains intact
what clears apoptotic cell fragments?
phagocytes
is there inflammation with apoptosis?
no
what initiates apoptosis in cancer?
tumor suppressor gene p53 in response to damage
mutations in p53 lead to cancer
what is the appearance of an apoptotic cell?
single cell or small cluster
cell shrinkage
chromatin condensation
formation cytoplasmic blebs and apoptotic bodies
what is part of the intrinsic pathway of apoptosis?
mitochondrial: cytochrome c, protein misfolding
proteins that maintain mitochondrial permeability
what pathway to apoptosis involves a death ligand and receptor?
extrinsic apoptotic pathway
what are the nuclear characteristics of necrosis?
pyknosis
karyorrhexis
karyolysis
what are the nuclear characteristics of apoptosis?
pyknosis
karyorrhexis
what are the general features of necrosis?
inflammation unless hyperacute
loss of adherence
nuclear changes
calcification
cytoplasmic changes
where is coagulative necrosis classically seen?
kidney
liver
muscle
what is liquefactive necrosis mediated by?
inflammatory cell enzymes
neutrophils, macrophages
what is pancreatic fat necrosis?
pancreatic enzymes cause release of fatty acids from dying adipocytes
what causes nutritional fat necrosis?
vitamin E deficiency
what type of necrosis is dry gangrenous necrosis?
coagulative
what is autophagy?
when a cell digests its own organelles
what is it called when necrotic debris calcifies (especially in caseous necrosis)?
dystrophic calcification
dry gangrenous necrosis develops in extremities that have undergone ____________________, i.e. frostbite, fescue toxicity
coagulation necrosis
how is necrosis healed?
complete restitution or fibrosis
what can pathologic apoptosis be from?
radiation
anti-neoplastic drugs
viruses
cell death in tumors
misfolded proteins
DNA damage
what nuclear change is unique to necrosis?
karyolysis is only in necrosis, not in apoptosis
