The Ist change occurring in a sharp cut nerve is:
Correct Answer: Degeneration of myelin sheath
Description: 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 :,tiiiiip. Wallerian degeneration.Q upto nearest node of ranvier grows & sprout out (pseudopod * Within 24 hours histological and chemical changes occur (nearest collateral)Q 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 (K/a * 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 & K/a ghost tube. in 80 days. 1s1 change in cut nerve is - Axonal degeneration 2nd change in cut nerve is - Myelin degeneration
Category:
Physiology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now