Which description matches axonotmesis (Type 2 nerve injury)?

Which description matches axonotmesis (Type 2 nerve injury)?

• A. Conduction Block
• B. Neurotmesis
• C. Axonotmesis
• D. Demyelination

Answer: (C)

In axonotmesis, the axon and its myelin sheath are disrupted, and the part of the axon distal to the injury undergoes Wallerian degeneration. However, the surrounding connective tissue scaffold, especially the endoneurium, remains intact. That preserved framework provides guiding tubes for the regrowing axons, so regeneration can occur along the original path toward the target muscles or sensory areas. Because the axon is damaged but the scaffold is preserved, this type of injury has an intermediate prognosis: better than a complete nerve transection, but not as favorable as a neurapraxia where the axon isn’t damaged. To connect with the other concepts: conduction block happens with preserved axons but impaired conduction (neurapraxia) without axonal injury. Demyelination involves loss of myelin with an intact axon, slowing or blocking conduction but not causing axonal degeneration. Neurotmesis is a complete severing of the nerve with disruption of the axon and all surrounding connective tissue, making regeneration far more challenging. So, the best match is an injury where the axon is damaged and distal axonal degeneration occurs, but the supporting tissue scaffolding remains intact, allowing regrowth along the original pathways.

In axonotmesis, the axon and its myelin sheath are disrupted, and the part of the axon distal to the injury undergoes Wallerian degeneration. However, the surrounding connective tissue scaffold, especially the endoneurium, remains intact. That preserved framework provides guiding tubes for the regrowing axons, so regeneration can occur along the original path toward the target muscles or sensory areas. Because the axon is damaged but the scaffold is preserved, this type of injury has an intermediate prognosis: better than a complete nerve transection, but not as favorable as a neurapraxia where the axon isn’t damaged.

To connect with the other concepts: conduction block happens with preserved axons but impaired conduction (neurapraxia) without axonal injury. Demyelination involves loss of myelin with an intact axon, slowing or blocking conduction but not causing axonal degeneration. Neurotmesis is a complete severing of the nerve with disruption of the axon and all surrounding connective tissue, making regeneration far more challenging.

So, the best match is an injury where the axon is damaged and distal axonal degeneration occurs, but the supporting tissue scaffolding remains intact, allowing regrowth along the original pathways.