Cell Injury Mechanisms PDF

1-CELL INJURY b-Mechanisms of Cell Damage Prof. Dr. Emrullah Beyazyıldız 05057669683  The most common cause of clinically significant cell damage is...

1-CELL INJURY b-Mechanisms of Cell Damage Prof. Dr. Emrullah Beyazyıldız 05057669683  The most common cause of clinically significant cell damage is hypoxia. The most common cause of hypoxia ISKEMI is ischemia due to arterial occlusion CELL H2O H2O Mitocho ndria Oxidative H2O Phosphorylation ATP Na-K pump H2O cannot work H2O Decreas es N N N N a a a a  Acute cellular swelling The first morphological change in hypoxia Cellular swelling is the first cellular change seen morphologically in cell damage. The first organelle to be affected in a hypoxic cell is the mitochondria. The first system affected in a hypoxic cell is aerobic respiration. Cellular swelling and lubrication are the first morphologic findings observed on light microscopic examination.  It decreases2 Na-K pump can't work Anaerobic Protein Synthesis Glycolysis decreases Increased Na, H2O, Ca increases entry into the cell Glycogen Intracellular lipid K output increases Decreases accumulation Lactic Acid Cell and ER swell Increases (pH Microvilli disappear decreases) Chromatin aggregation and coarsening Ca pump ATPase Phospholipa Cytochro se me c Protease Endonucleas e Kaspaz 9 Apoptosis The function of the calcium pump is impaired by ATP depletion. Calcium increases inside the cell. 1.Increased intracellular calcium causes cell death by activating ATP'az, phospholipase, protease and endonuclease enzymes (phospholipid damage, cell membrane damage and fragmentation of cytoskeletal proteins and nuclear chromatin damage). 2.Calcium disrupts mitochondrial permeability, increases cytochrome C efflux and initiates apoptosis by activating caspases. (Cytochrome c activates caspase 9.) 1.Substances decreased in hypoxic cells: Potassium, Protein, Glycogen and ATP. 2.Substances increased in hypoxic cells: ADP, Inorganic phosphates, Na, Chlorine, Calcium, Purine nucleosides, Lactic acid and water.