cell injury Flashcards
what is the effects of cell stress dependent on
intensity of stressor (e.g touching candle)
vulnerability (cardiac > skeletal).
5 causes of cell injury
hypoxia - no O2 supply
ischaemia - reduced blood supply
physical agents - mechanical trauma, extreme temps , radiation
infectious agents - bacteria, viruses, fungi
nutritional imbalance - anorexia, scurvy etc
immunological reactions - anaphylaxis, autoimmune reactions
what gets disrupted in cells during reversible injury
aerobic respiration therefore ATP production due to mitochondrial damage
plasma membrane integrity
enzyme and structural protein synthesis
what happens to cell morphology during reversible cell injury
cloudy swelling - influx of Na and H2O due to failure of ATP dependent pumps
fatty change - accumulation of lipid vacuoles in the cytoplasm
what are examples of irreversible cell injury/ changes
membrane rupturing
dispersal of organelles
breakdown of lysosomes
what are examples of changes seen in reversible cell injury
dilation of organelles
ribosome disaggregation
necrosis
cell death due to pathology
results in inflammatory response in surrounding tissues
apoptosis
genetically programmed cell death
histologically, what does a cell destroyed by necrosis look like
either no nucleus or a shrunken darker stained nucleus
paler cytoplasm as it is swollen
coagulative necrosis
no proteolysis due to denaturation of enzymes
no nucleus
architechture preserved for a couple of days
liquefactive necrosis
tissue transforms to thick viscous mass (pus)
absecceses, fungal infections etc..
caseous necrosis
mostly seen in tuberculosis infection
fibrinoid necrosis
special type seen in immune reactions in blood vessels
why does necrosis cause inflammation
cell contents released and remains need to be phagocytosed
what is a necrotic area replaced by
scar
what do the nuclei and cytoplasm tell you about a necrotic cell
nuclei tells you if the cell has died, cytoplasm tells you how the cell has died
what are examples of pathological triggers of apoptosis
hypoxia/ ischaemia
dna damage
viral infections
what can too little or too much apoptosis result in
too much - degenerative diseases
too little - cancer
amyloid proteins
abnormal proteins capable of causing disease. Cant be removed if patients suffers from amyloidosis
what does apoptosis do in regards to cell morphology
cell shrinkage
intact membrane
phagocytosed but no inflammation
apoptosis vs necrosis cell size nucleus membrane contents inflammation
shrink. enlarge
fragmentation. loss
intact ruptured
intact leakage
no. yes
