apoptosis and necrosis Flashcards
what is apoptosis
Non inflammatory programmed cell death
what protein detects DNA damage
p53
how does a cell apoptose
-cell triggers a series of proteins which lead to release of enzymes within the cell which eventually autodigest the cell
role of apoptosis in development
removal of cells during development e.g.
interdigital webs
role of apoptosis in cell turnover
removal of cells during development e.g.
interdigital webs
define necrosis
destruction of large numbers of cells by an external factor
eg- frostbite, spider venom , pancreatitis
Anti apoptotic proteins ?
BCL 2
BCL x
Pro apoptotic proteins
BAX
BAK
How does the intrinsic pathway for apoptosis work
Cell damage causes blockage of anti proteins
Bax and bak proteins are free so cytochrome c is released from mitochondrial membrane
CC binds to ADAF proteins to start caspace cascade
Most common type of necrosis
Coagulative necrosis
Cause by ischaemia
Example of liquefactive necrosis
Occurs in brain due to lack of substantial supporting stroma
inhibitors of apoptosis
growth factors
sex steroids
extracellular matrix
inducers of apoptosis
glucocorticoids
free radicals
ionising radiation
DNA damage
what is gangrene and how does it appear
necrosis with rotting of the tissue
affected tissue appears black due to deposition of iron sulphide
Extrinsic pathway of apoptosis
Fas l or TNF L binds to csm receptors which activates caspases
