This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nerve Injuries - 1, Subject name: Orthopaedics
Wallerian degeneration involves: 
Select and explain. 
A. Chromatolysis., B. Only the CNS., C. Successive fragmentation of the axon., D. Swelling of the cell body
C: Successive fragmentation of the axon.
Answer: C: Successive fragmentation of the axon. 
Explanation: Wallerian, or anterograde degeneration Occurs toward the distal end of the axon in both the CNS and PNS Characterized by successive fragmentation and disappearance of axons and myelin sheaths and by secondary proliferation of Schwann cells. Retrograde degeneration occurs toward the proximal end of the axon and in the cell body. Takes place in both the CNS and PNS Characterized by chromatolysis, cell body swelling, and flattening and displacement of the nucleus to the periphery