Definition

Noun: A nerve fiber that is encased in a sheath of myelin. This myelin sheath is a fatty, insulating layer that surrounds the axon of the neuron, enabling faster and more efficient transmission of electrical impulses along the nerve fiber.

Usage

This is a specialized anatomical and physiological term used primarily in neuroscience, biology, and medicine. - It refers to a specific physical structure within the nervous system. - It is often contrasted with non-medullated or unmyelinated nerve fibers, which lack this insulating sheath.

Examples

• Under the microscope, the medullated nerve fiber appeared distinctly white due to its myelin coating.
• The rapid reflex arc is facilitated by signals traveling along medullated nerve fibers.
• Damage to the myelin sheath of a medullated nerve fiber can lead to impaired neural communication, as seen in multiple sclerosis.

Advanced Usage

• The term is frequently used in histological descriptions and textbooks to classify types of neural tissue.
• In clinical contexts, the integrity of medullated nerve fibers is assessed in diagnosing certain neurological disorders.

Variants and Related Words

• Myelinated nerve fiber: A direct synonym; "myelinated" and "medullated" are often used interchangeably in this context.
• Myelin sheath: The insulating covering itself.
• Axon: The long, slender projection of a neuron that is typically myelinated in medullated fibers.
• White matter: Regions of the central nervous system rich in collections of medullated nerve fibers, giving it a white appearance.

Synonyms

• Myelinated nerve fiber
• Myelinated axon

Antonyms

• Non-medullated nerve fiber
• Unmyelinated nerve fiber

Noun

1. a nerve fiber encased in a sheath of myelin