myelin

Thân thiện

A scientist examines a diagram showing myelin sheaths around nerve fibers.

Definition

Noun: * A white, fatty substance that forms an insulating layer (the myelin sheath) around the axons of many neurons. Its primary function is to increase the speed at which electrical impulses (nerve signals) travel along the nerve fiber.

Usage

Myelin is a biological term used specifically in the fields of neuroscience, neurology, and medicine. It refers to the essential insulating material of the nervous system.

Examples

• In a biological context:
  • The rapid transmission of signals in the nervous system depends on the integrity of the myelin.
  • Diseases like multiple sclerosis involve the degradation of myelin.
  • The axon is surrounded by a protective layer of myelin.

Advanced Usage

• "Myelination" (noun): The process by which myelin is formed and deposited around an axon.
  • The myelination of nerve fibers continues through childhood and adolescence.
• "Demyelination" (noun): The pathological loss or damage of the myelin sheath.
  • The primary symptom is caused by demyelination in the central nervous system.
• "Remyelination" (noun): The process of repairing or regenerating the myelin sheath.
  • Researchers are studying ways to promote remyelination after injury.

Variants and Related Words

• Myelin sheath (noun phrase): The entire insulating covering, composed of myelin and the cells that produce it, that surrounds an axon.
• Myelinated (adjective): Describing a nerve fiber that is encased in a myelin sheath.
  • Myelinated axons conduct impulses faster than unmyelinated ones.
• Myelinic (adjective): Of or relating to myelin.
• Myelinolysis (noun): The dissolution or destruction of myelin.

Synonyms

• Medullary sheath (an older, less specific term)
• White matter (refers to brain and spinal cord tissue that is rich in myelinated axons)

Notes on Meaning

The term myelin has a single, highly specific meaning in scientific English. It does not have common idiomatic or phrasal verb uses. All its applications are directly related to its role in the nervous system.

Học thuật

Noun

1. a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibers

Từ đồng nghĩa

• myeline
• medulla