Cell death Flashcards
(18 cards)
Describe quickly the steps to necrosis and to apoptosis
Normal cell undergoes swelling and blebs which in turn leads to enzymatic digestion and leakage of cellular contents > Necrosis
Normal cell undergoes apoptosis which leads to phagocytosis of the apoptotic cells and fragments > apoptosis
Necrosis
1) what are the morphological changes like
2) how does this cell death happen?
3) what is necrosis not controlled by
1) spectrum of morphological changes following cell death in living tissue
2) happens without participation of the cell
3) always a pathological process, something that is not controlled by the host
Morphology necrosis
1) increased eosinophilic staining means what?
2) Vacuolation meaning what
3) Swelling of what?
4) Whorls of phospholipid from damaged membranes
5) nuclear change due to what?
1) denatured protein and loss of RNA
2) digested cytoplasmic organelles
3) swelling of ER and mitochondria
4) myelin figures
5) duue to breakdown of DNA and chromatin.
What are the following
a) karyolysis
b) pyknosis
c) kayorrhexia
a) decreased basophilia from DNA breakdown
b) nuclear shrinkage and increased basophlia (condensed)
c) nuclear fragmentation
Appearance of necrotic lesion is influenced by the balance of what 2 things and explain them
1) Coagulative where there is denaturation of proteins and the cells are dead but the tissue architecture is preserved
2) Liquefactive where there is enzymatic digestion of all macromolecules and so cells are digested with no tissue structure
What are 6 types of necrosis
Coagulative Liquefactive Caseous Fat Gangrenuous Fibrinoid
Coagulative necrosis
1) which is more overpowering, denaturation or digestion?
2) what happens in this
3) due to what
1) denaturation > digestion
2) nucleus is lost and architecture of cells preserved
3) due to severe ischaemia, occurs in solid organs
Liquefactive necrosis
1) which is more overpowering, denaturation or digestion?
2) what happens in this
3) due to what
4) what happens when there is ischemia in the brain
1) digestion > denaturation
2) associated with infection so with bacterial and fungal.
3) inflammatory response contributes to digestion of tissue
4) necrotic area becomes fluid filled cyst
Caseous necrosis
1) which is more overpowering, denaturation or digestion?
2) what happens in this
3) associated with what?
4) what appearance
1) denaturation and digestion
2) tissue arch obliterated
3) associated with centre of infection of mycobacterium tuberculosis
4) fragmented lysed cells with amorphous granular appearance
Fat necrosis
1) refers to what?
2) enzymes liquefy what?
3) releasewhat which combine with what to case what?
4) most common where
1) refers to focal areas of fat destruction
2) enzymes liquefy membranes of fat cells
3) release fatty acids which combine with calcium to cause patchy white lesions - fat saponification
4) most common in acute pancreatitis
fibrinoid necrosis
1) occurs where in response to what?
2) associated with what
1) occurs in blood vessels in response to deposition of immune complexes
2) associated with leakage of fibrin and inflammatory cells
Gangrenuous lower limb necrosis
1) usually describes what
2) what other necrosis my accompany this
1) occurs in a lower limb which has lost its blood supply
2) many accompany a bacterial infection such as wet gangrene
Apoptosis
1) physio or patho?
1) regulated form of cell death which may be both physiological and pathological
Morphology of apoptosis
1) eosinophils?
2) chromatin
3) cell size
4) inflammatory response?
5) phagocytosed or nah?
1) intensely eosinophilic cytoplasm
2) nuclear chromatin condensation and fragmentation
3) cells shrink
4) no inflamm response
5) phagocytosed yes
what are the physiological induction of apoptosis?
Embryogenesis
Involution
Cell loss in proliferating cell population
elimation of cells that reached their used by date
self reactive t lymphocytes
Pathological induction of apoptosis (5)
Growth factor deprivation DNA damage Acuumulation of misfolded protein Cell injuy in infection pathologic atrophy
What are the 2 apoptotic pathways?
Mitochondrial (intrinsic) Death receptor (extrinsic)
Describe the intrinsic pathway and how its induced
Induced by cell injury
- growth factor withdrawal
- dna damage by radiation etc
- protein misfolding (ER stress)
The intrinsic pathway is
- Bcl 2 family sensors
