What is neurilemma?

What is neurilemma?

• A. helps CNS axons to regenerate
• B. protects CNS axons from injury
• C. helps PNS axons to regenerate
• D. forms the blood-brain barrier

Answer: (C)

Neurilemma is the outermost layer formed by Schwann cells around a peripheral nerve fiber. It stays with the axon after injury and creates a regeneration tube that guides axonal regrowth, while Schwann cells secrete growth factors and extracellular matrix to support the process. This environment enables peripheral nerves to regenerate more effectively than those in the CNS, where a neurilemma isn’t present and regeneration is limited by other factors. The blood-brain barrier is a different structure formed by endothelial tight junctions and astrocyte interactions, not by neurilemma. So the neurilemma’s role is to help peripheral nerve axons regenerate.

Neurilemma is the outermost layer formed by Schwann cells around a peripheral nerve fiber. It stays with the axon after injury and creates a regeneration tube that guides axonal regrowth, while Schwann cells secrete growth factors and extracellular matrix to support the process. This environment enables peripheral nerves to regenerate more effectively than those in the CNS, where a neurilemma isn’t present and regeneration is limited by other factors. The blood-brain barrier is a different structure formed by endothelial tight junctions and astrocyte interactions, not by neurilemma. So the neurilemma’s role is to help peripheral nerve axons regenerate.