necrosis and cell damage Flashcards
causes of cell injury
chemical physcial infective hypoxia immune
responses to cell injury
stress
injury
what adaptations occur upon stress to the cell
hyperplasia - inc in num
hypertrophy
atrophy
metaplasia
what does injury to the cell lead to
necrosis or apoptosis
targets to cell injury
energy metabolism
cell membrane
protein synthesis
genes
explain injury to energy metabolism
hypoxia or mitochondrial dysfunction prevents formation of ATP
lactic acid build up due to anaerobic respiraton
membrane damage
damage to phospholipid can lead to lysis
mitochondria - impairs energy metabolism
damage to lysosomes
releases hydrolytic membranes
cells may digest themselves
damage to ER
interferes with protein synthesis
what does calcium affect
ATPase - decrease in ATP
phospolipase - breakdown of phospholipid
proteases - cytoskeletal digestion
how can calcium homeostasis be lost
damage to membranes, influx of Ca from organelles
how are free radicals produced
radiation
examples of radical
hydroxyl
hydrogen peroxide
superoxide anion
what counteract radicals
SOD (superoxide dismutase)
Vitamin K
Catalase
Vitamin E
how is the superoxide anion neutralsied
using SOD to H202
catalase to water
what are neutralisers of free radicals called
anti oxidants
what do free radicals do
initiate chain reactiosn
effects of reactive oxygen species
membrane damage
cross link proteins
DNA strand breakage
linking common signals example
damage to mitochondrial membrane
release of Ca into cell (affecting Ca homeostasis)
increase activity of ATPase
depletion of ATP in cell
may lead to some membrane pumps not working
necrosis VS apoptosis
affects many cells VS 1
causes secondary inflammatory vs no secondary effect
cell swelling vs cell shrinkage
disruption to the membrane vs no disruption (membrane blebbing)
random fragmentation of nucleus vs DNA laddering, nuclear condensation dissolution
what happens to the apoptotic bodies
consumed by leukocytes
types of necrosis
coagulative
Fat
liquefactive
caseous
what happens in coagulative necorsis
nucleus fades and dissolves (karyolysis) nuclear fragmentation(karyorrhexis)
eosinophilic cytoplasm
what causes coagulative necrosis
lack of blood supply
what happens in liqefactive necross
tissue liquified by PMN(polymorphonuclear) enzymes
what happens in caseous
combination of coagulative and liquefaction
what happens in fat necrosis
release of pancreatic lipases in acute pancreatitis
examples of cell damage and necrosis in dentistry
pupal necrosis interruption of blood supply pulpits abcess osteonecrosis of jaw
sequelae of cell injury
inflammation
repair
scar
fibrosis
