neurolemma
Học thuậtThân thiện
Definition
Noun: A thin, membranous sheath that surrounds the axon (nerve fiber) of a neuron. It is the outermost layer of the Schwann cell in the peripheral nervous system.
Usage
The term "neurolemma" is used specifically in the context of neuroanatomy and histology to describe the protective covering of a nerve fiber. * The neurolemma is essential for the regeneration of damaged peripheral nerves. * Under the microscope, you can observe the neurolemma enveloping the axon.
Advanced Usage
- Role in Nerve Repair: The neurolemma forms a tubular structure that guides the regrowth of an axon after injury, a function critical in the peripheral nervous system but absent in the central nervous system (which lacks a neurolemma).
- The presence of an intact neurolemma significantly improves the prognosis for nerve recovery.
Variants and Related Words
- Neurilemma: An alternative spelling for "neurolemma." Both forms are accepted.
- Sheath of Schwann: A synonym that directly references the Schwann cell from which the neurolemma is derived.
- Endoneurium: A layer of connective tissue that surrounds individual nerve fibers and their neurolemma within a peripheral nerve. (Note: This is a different, surrounding structure).
- Myelin Sheath: The fatty, insulating layer beneath the neurolemma in myelinated axons. The neurolemma surrounds the myelin sheath.
Synonyms
- Sheath of Schwann
- Neurilemma
Noun
- thin membranous sheath around a nerve fiber