<prompt> The Ist change occurring in a sharp cut nerve is:Schwann cells proliferationDegeneration of myelin sheathChromatolysisDegeneration of neurilema  <response>: B i.e. Degeneration of myelin sheath Changes in Nerve Fiber after Injury Degeneration of the distal pa Antegrade Degeneration of proximal pa Retrograde Stage of Regeneration Degeneration of distal pa distal to cut is called Same as distal generation hut Axis cylinder:, from :,tiiip. Wallerian degeneration.Q upto nearest node of ranvier grows sprout out pseudopod Within 24 hours histological and chemical changes occur nearest collateralQ like structure of fibril The axon cylinder swells up breaks down into small Changes in the cell body: After 2-3 weeks peripheral rodlets.Q - Within 48 hours of injury the endoneural tube, contain Myelin sheath breaks down into oily droplets, It occurs nissl granules begins to varying no of developing fibril 8-32 days after injury.Q disintegrate Ka Medullary sheath begins to Cells of the sheath of Schwann - divide mitoticallyQ chromatolysis develop in about 15 days from cords of cells lying within the endoneurial tube - Golgi apparatus fragments completed within one year. neurilemma -- macrophages remove the degenerating - Cells swell Repair of cell body i.e. Nissl myelin axis cylinder -s thus schwann cell cytoplasm - Neurofibril disappear granules golgi apparatus -- gradually fills the neurilemma, this process is completed by nucleus displaced to cell begins about 20 days after 3 months. margin. nerve section is completed Hollow tube of neurilemma remains intact Ka ghost tube. in 80 days. 1s1 change in cut nerve is - Axonal degeneration 2nd change in cut nerve is - Myelin degeneration 