MindMap Gallery Cell Injury
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Cell Injury
This is a mind map of cell injury. You can make and share your own mind maps easily. Just try EdrawMind mind mapping software for free! Cell damage (also known as cell injury) is a variety of changes of stress that a cell suffers due to external as well as internal environmental changes. Amongst other causes, this can be due to physical, chemical, infectious, biological, nutritional or immunological factors.
Edited at 2023-02-16 01:36:35
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- Outline
cell injurey
Injury
Reversible
Pathogenesis
Mitochondrial oxidative phosphorylation is disrupted first SO RED ATP SO
RED Na/K ATPase SO INCintracellular Na SO cell swelling
RED ATP-dependent Ca pumps SO INC cytoplasmic [Ca]
Anaerobic respiration SO RED glycogen
Lactic acid accumulation SO RED pH
Detachment of ribosomes from RER SO RED protein synthesis
End result is cytoskeletal disruption with loss of microvilli, bleb formation, etc
Morphology
Light microscopic changes
Cell swelling (i.e., hydropic change)
Fatty change
Ultrastructural changes
Alterations of cell membrane
Swelling of and small amorphous deposits in mitochondria
Swelling of RER and detachment of ribosomes
LEADS TO
Recovery
Irreversible
Pathogenesis
Mitochondrial swelling with formation of large amorphous densities in matrix
Lysosomal membrane damage leakage of proteolytic enzymes into cytoplasm
Membrane damage and loss of calcium homeostasis are most crucial
Too much cytoplasmic calcium
Denatures proteins
Poisons mitochondria
Inhibits cellular enzymes
Morphology
Light microscopic changes
Increased cytoplasmic eosinophilia (loss of RNA, which is more basophilic)
Cytoplasmic vacuolization
Nuclear chromatin clumping
Ultrastructural changes
Breaks in cellular and organellar membranes
Larger amorphous densities in mitochondria
Nuclear changes
Pyknosis
Nuclear shrinkage and increased basophilia
Karyorrhexis
Fragmentation of the pyknotic nucleus
Karyolysis
Fading of basophilia of chromatin
LEADS TO
Cell death
Necrosis
Apoptosis
causes
Hypoxia and ischemia
Pathogeneses
Hypoxia ≠ Ischemia
Hypoxemia: reduce of oxygen carrying capacity
Ischemia: reduce blood supply
SO rapidlyRED oxygen and glycogen + metabolites accumulate and are not carried away by circulation (more rapid and severe acidosis)
Lead to faliure of many energy dependant metabolic pathways SO failure RED of ATP SO death
Consecunses
Block in ventilation (e.g., foreign body)
Block in diffusion of oxygen (e.g., pneumonia, pulmonary edema)
Block in perfusion (e.g., pulmonary embolus)
Decreased cardiac output
Decreased oxygen carrying capacity (e.g., anemia)
Ischemia (e.g., blockage of blood flow)
Free radical damage
Oxidative Stress
Free radicals have an unpaired electron in their outer orbit and it cause cellular chain reactions generated by
Absorption of radiant energy
Oxidation of endogenous constituents
Oxidation of exogenous compounds
Examples of Free Radical Injury
Chemical (e.g., acetaminophen)
Inflammation / Microbial killing
Irradiation (e.g., UV rays skin cancer)
Oxygen (e.g., exposure to very high oxygen tension on ventilator)
Age-related changes
Mechanism of Free Radical Injury
Lipid peroxidation SO damage to phospholipids (cellular and organellar membranes) and proteins
Oxidized phospholipids and proteins are not readily broken down SO accumulate and aggregate
Protein cross-linking and fragmentation due to oxidative modification of amino acids and proteins
DNA damage due to reactions of free radicals with thymine
Chemicals, drugs, toxins (e.g., acids, bases, organo-phosphates)
Environmental chemicals and substances produced by infectious pathogens SO injury SO death
Direct-acting toxins e.g., HgCl2
Latent e.g., CCl4
Infections
Aging
Endoplasmic Reticulum Stress
INC Production of misfolded proteins + RED elimination of them can stress compensatory pathways in the ER SO injury SO death
Immunologic reactions
Genetic abnormalities (e.g., storage diseases, enzyme deficiencies)
Nutritional imbalance (e.g., protein or calorie malnutrition)
Physical agents
CELL INJURY HAPPENS ONLY IN THE CELL CLOUDN'T ADAP
Ischemia Reperfusion Injury
Paradoxically increase cell injury
Inflammation that is induced by ischemic injury may increase with reperfusion
INC ROS ( by injured cells and infiltrating leukocytes)