cell injury Flashcards
(26 cards)
irreversible cell injury can lead to
necrosis and apoptosis
what are the targets of cell injury
- mitochondria
- cell membrane
- nucleus
mitochondria are damaged by
cytosolic Ca++, ROS, o2 deprived toxins
mitochondria damage causes
decrease ATP, decrease na/k atpase pump , decrease glycogen storage, increase lactic acid
decrease in na/k ATPase causes
cellular swelling ( sodium and water get trapped)
injury to cell membrane causes
-loss selective permeability
- decrease o2= phospholipid loss
- increase Ca2+ causes lipid breakdown
DNA damage is done by
radiation
DNA damage activates
activates sensors which trigger p53 dependent pathway
activation of p53 causes
-cells to stop in G1
- activates DNA repair
- can trigger apoptosis
- ass. with cancers
ishemia-reperfusion injury is the
return blood flow
re-oxygentation (ishemia) causes
increase in production of reaction oxygen species
intracellular calcium can also cause
mitochondrial damage
Disruption in calcium homeostasis causes
- increase calcium in cytoplasm
- activation of enzymes leading to membrane and chromatin damage causing decrease in ATP
what components of the inflamation system secrete products and what do those products do
- neutrophils, macrophages, lymphocytes
- destroy microbes but can injure the cell
what oxidative stress induced by
ROS ( reactive oxygen species)
What do ROS attack
nucleic acids, lipids, protein
removal of ROS is by
spontaneous decay
what are the three free radical scavengers
- superoxide dismutase
- glutathione
- catalase
what vitamins block formation of free radicals
Vitamin A,E,C and beta-caratone
latent toxin..
converts to reactive metabolites affecting the cells
direct acting toxin..
combines with critical molecular component
latent toxin affects
smooth ER of liver and other organs
latent toxins are mainly due to
production of free radicals
what three things causes aging
- ROS
- Telomere shortening
- defective protein homeostasis
