Flashcards in Pathology - First Aid Deck (206)
Both the intrinsic and extrinsic pathways for apoptosis activate...
cytosolic caspases that mediate cellular breakdown.
Unlike necrosis, apoptosis does not have...
Apoptosis is charachterized by..
deeply eosinophilic cytoplasm, cell shrinkage, nuclear shrinkage (pyknosis) and basophilia, membrane blebbing nuclear fragmentation (karyorrhexis), and formation of apoptotic bodies, which are then phagocytosed.
DNA laddering is a...
sensitive indicator of apoptosis.
Durrying karyorrheix, endonucleases will...
cleave at internucleosomal regions, yielding 180-bp fragments.
Radiation therapy causes...
apoptosis of tumors and surrounding tissue via free radical formation and dsDNA breakage.
Intrinsic apoptosis pathway is invovled in..
tissue remodeling in embryogenesis.
Intrinsic pathway occurs when...
a regulating factor is withdrawn from a proliferating cell population (ex. decreased IL-2 after a completeed immunological rxn leads to apoptosis of proliferating effector cells).
Intrinsic pathway also occurs after exposure to...
injurious stimuli (radiation, toxins, hypoxia).
During the intrinsic pathway, changes in proportions of...
anti- and pro- apoptotic factors lead to increased mitochondrial permeability and cytochrome c release.
BAX and BAK are...
cytochrome c release by binding to and inhibiting Apaf-1.
induces the activation of caspases.
If Bcl-2 is overexpressed, then...
Apaf-1 is overly inhibitedd, leading to decreased caspase activation and tumorigenesis.
2 pathways of the extrinsic apoptosis pathway
1. ligand receptor interactions (FasL binding to Fas)
2. immune cell (cytotoxic T-cell release of perforin and granzyme B)
Fas-FasL interaction is necessary in...
thymic medullary negative selection.
Mutations in Fas incnresae...
numbers of circulating self-reacting lymphocytes due to failure of clonal deletion.
After Fas crosslinks with FasL...
multiple Fas molecules coalesce forming a binding site for a death domain-containing adapter protein, FADD.
inactive caspases, activating them.
Defective Fas-FasL interaction is the basis for...
-heart, liver, kidney
-occurs in tissues supplied by end-arteries
-increased cytoplasmic binding of acidophilic dye
-proteins denature first, followed by enzymatic degradation
-brain, bacterial abscess
-occurs in CNS due to high fat content
-enzymatic degradation is due to the release of lysosomal enzymes
-TB, systemic fungi, nocardia
-enzymatic (pancreatitis (saponification)) and nonenzymatic (breast trauma); calcium deposits appear dark blue on staining
-vasculitides (Henoch-Schonlein purpura)
-amorphous and pink
-dry (ischemi coagulative) and wet (infxn)
-common in limbs and GI tract
Reversible cell injury (w/ O2)
1. ATP depletion
2. cellular/mitochondrial swelling
3. nuclear chromatin clumping
4. decreased glycogen
5. fatty change
6. ribosomal/polysomal detachment
7. membrane blebbing