<prompt> Which of the following is the characteristic of irreversible injury on electron microscopyDisruption of ribosomesAmorphous densities in mitochondriaSwelling of Endoplasmic reticulumCell swelling  <response>: Ans. b. Amorphous densities in mitochondria One of the characteristic features of irreversible injury on electron microscopy is marked dilation of mitochondria with the appearance of large amorphous densities Cell Injury Reversible injury Occurs due to widespread effects of depletion of ATP decreased activity of NW-K. ATPase, which occurs as a result of hypoxiaQ Features of reversible injury: Cellular swelling Loss of microvilliQ Bleb formationQ ER swelling: Detachment of ribosomesQ Myelin figures Nuclear: Clumping of nuclear chromatinQ Irreversible injury Membrane damage is a central factor in pathogenesis of irreversible injury. Features of irreversible injury include: A Severe swelling of mitochondria: Large,flocculant amorphous densities develop in mitochondria! matrix Increased Ca influx B Severe swelling of lysosomes: Injury to lysosomal membrane follows, various enzymes are released leading to: Decreased basophiliaQ Nuclear changes Pyknosis, karyolysis, Karyorrhexis Protein digestionQ C. Severe damage to plasma membraneQ 