Types And Mechanisms Of Cell Injury Flashcards
What is injury
Set of biochemical and or morphological changes that occur when the state of homeostasis is disturbed by adverse influences
What are causes of cell injury
Hypoxia:def of O2 Physical agents Chemical agents and drugs Infectious biological agents Immunologic reactions Genetic abnormalities Nutritional imbalances Aging
What are causes of hypoxia
Ischemia due to red atrial blood flow
Cardiorespiratory failure
Reduced oxygen carrying capacity
What does cellular response to injury to depend on
Nature duration and severity
What do the consequences of injury depend on
Type state and adaptability of cell
Reversible injury
Condition which is capable of being reversed with restoration of previous state of cells following removal of adverse influences
Irreversible injury
Occurs where injurious stimulus is persistent or severe and cellular changes are not able to be undone or return back to normal status and ultimately undergo cell death
What does cell injury result from(disturbance)
Atp production Mitch integrity independent of Atp Plasma membrane integrity Protein synthesis Integrity of genetic app
What are consequences of ATP depletion
Failure of membrane transport and NA pump
Increased anaerobic glycolysis
Reduced protein synthesis
What are the reversible consequences of ATP depletion
Failure of active plasma membrane transport leads to: ATP depletion, cellular swelling, mitch swelling, dilation of sarcoplasmic reticulum, reduction in protein synthesis, inc intracellular lipid accumulation
What are the irreversible consequences of ATP depletion
Increased rate of anaerobic glycolysis With depletion of: Glycogen stores Reduced intracellular PH Dec activity of many cellular enzymes Chromatin clumping and disruption of cell organelles including lysosomes Influx of Ca2+
How are mitochondria damaged
Inc of Ca2+
Reactive oxygen species
Ischemia
Mutations in mitch genes
What are causes membrane damage
Ischemia, bacterial toxins, viral proteins, lytic components, variety of physical and chemical agents
What are consequences of membrane damage
Mitch membrane damage
Plasma membrane damage
Injury to lysosomal membranes
What are causes of DNA damage
Exposure to radiation,chemotherapeutic drugs ,ROS and aging
What are consequences of DNA damage
Damage to nuclear DNA sensors that trigger p53 dependent pathways which arrest cells in the G1 phase of cell cycle and activates DNA repair which can impair its ability to induce apoptosis
What ROS
group of mol with a highly reactive O2
Might be due to presence of an O2 mol or an unpaired electron in outer most shell or produced by leakage from damaged mitch
What are the adverse effects of ROS
Damage to:
Lipid per-oxidation in plasma membranes and organellar membranes which result in extensive membrane damage
Protein oxidation and fragmentation of peptide bonds leading to damage of enzymes
Nucleic acids: oxidative DNA damage has been implicated in cell aging and malignancy
How can cells be protected against ROS
antioxidants which inactivate them such as VITC (aqueous such as blood) or E AND A(nonpolar such as cell membrane)
What are causes of influx of calcium
Ischemia and toxins
What are consequences of influx of Ca2+
Accumulation of Ca2+ in mitch Increased cytosolic Ca2+ enzymes phospholipases which cause membrane damage and proteases which break down membrane proteins Endonuclease ATPpases
