Definition

Noun: - A sheath of connective tissue: The perineurium is a protective sheath, specifically composed of connective tissue, that surrounds and encloses a bundle (fascicle) of nerve fibers within a peripheral nerve.

Usage

The term is used in anatomical and medical contexts to describe a specific structural layer of a nerve. - Each fascicle of nerve fibers is wrapped in a layer called the perineurium. - The integrity of the perineurium is crucial for maintaining the proper microenvironment for nerve impulse conduction.

Advanced Usage

• Perineurial barrier: Refers to the selective diffusion barrier function provided by the perineurium, which helps maintain a stable ionic environment for the axons it encloses.
  • The perineurial barrier is essential for protecting nerve fibers from fluctuations in the surrounding tissue.

Variants and Related Words

• Perineurial (adjective): Of or relating to the perineurium.
  • The perineurial layer was carefully examined under the microscope.

Different Meanings

This word has a single, specific meaning in anatomy and histology. There are no common alternative meanings.

Synonyms

• Connective tissue sheath (descriptive synonym, though less precise).
• Nerve fascicle sheath (descriptive synonym).

Idioms

There are no idioms associated with this specific anatomical term.

Phrasal Verbs

There are no phrasal verbs associated with this term.

Noun

1. the sheath of connective tissue that covers a bundle of nerve fibers