What is the term for the degeneration that occurs in the first three days after a nerve injury?

What is the term for the degeneration that occurs in the first three days after a nerve injury?

• A. Axonotmesis
• B. Wallerian degeneration
• C. Neurotmesis
• D. Neuropraxia

Answer: (B)

Wallerian degeneration refers to the process that occurs when a nerve is injured, leading to the degeneration of the axon and myelin sheath distal to the site of injury. This degeneration begins approximately 24 to 48 hours after the injury and continues for several days. During this time, the axonal portion separated from the cell body deteriorates, and the myelin sheath starts to break down. Wallerian degeneration is a critical concept in understanding nerve injuries because it explains how the peripheral nerve regenerates and the timeline of cellular responses following injury. The other terms represent different types of nerve injuries. For instance, axonotmesis indicates a partial injury where the axon is damaged but the surrounding connective tissue remains intact. Neurotmesis is a complete nerve injury resulting in both axon and surrounding structures being severed, while neuropraxia represents a temporary block of nerve conduction, typically without axonal injury. Understanding these distinctions helps in diagnosing and managing nerve injuries effectively.

Wallerian degeneration refers to the process that occurs when a nerve is injured, leading to the degeneration of the axon and myelin sheath distal to the site of injury. This degeneration begins approximately 24 to 48 hours after the injury and continues for several days. During this time, the axonal portion separated from the cell body deteriorates, and the myelin sheath starts to break down. Wallerian degeneration is a critical concept in understanding nerve injuries because it explains how the peripheral nerve regenerates and the timeline of cellular responses following injury.

The other terms represent different types of nerve injuries. For instance, axonotmesis indicates a partial injury where the axon is damaged but the surrounding connective tissue remains intact. Neurotmesis is a complete nerve injury resulting in both axon and surrounding structures being severed, while neuropraxia represents a temporary block of nerve conduction, typically without axonal injury. Understanding these distinctions helps in diagnosing and managing nerve injuries effectively.