**Question:** True about Wallerian degeneration

A. Wallerian degeneration is a process that occurs after nerve injury, causing demyelination and axonal degeneration distal to the injury site.
B. Wallerian degeneration is a normal physiological process that occurs in healthy nerves to maintain their integrity.
C. Wallerian degeneration is a localized process affecting only the myelin sheath without affecting axons and neurons.
D. Wallerian degeneration is a delayed process triggered by neuronal stimulation or injury.

**Correct Answer:** B. Wallerian degeneration is a normal physiological process that occurs in healthy nerves to maintain their integrity.

**Core Concept:** Wallerian degeneration is a natural process that occurs in healthy nerves to support their homeostasis. It involves the dismantling of the myelin sheath and axonal degeneration distal to a nerve injury or damage, aimed at reducing the load on the remaining axon and preventing the spread of injury to the distal parts of the nerve.

**Why the Correct Answer is Right:** Wallerian degeneration is a normal process in healthy nerves, as it helps to maintain the overall health and function of the nervous system. By dismantling the myelin sheath and degenerating axons that are damaged or distant from the injury site, it prevents further damage to the nerve and reduces the load on the remaining axon.

**Why Each Wrong Option is Incorrect:**

A. This option is incorrect because Wallerian degeneration is not a pathological process caused by nerve injury but a normal physiological response to maintain nerve homeostasis.
C. This option is incorrect because Wallerian degeneration specifically affects the myelin sheath and axons, not neurons or the myelin sheath alone.
D. This option is incorrect because Wallerian degeneration is an immediate response to nerve injury, not a delayed process triggered by neuronal stimulation or injury.

**Clinical Pearl:** Understanding the role of Wallerian degeneration in maintaining nerve health and preventing further damage after injury can help medical professionals provide better care and prognosis to patients with peripheral nerve injuries.