Also found in: Thesaurus, Medical, Wikipedia.


 (pĕr′ə-no͝or′ē-əm, -nyo͝or′-)
n. pl. per·i·neu·ri·a (-no͝or′ē-ə, -nyo͝or′-)
The sheath of connective tissue enclosing a bundle of nerve fibers.

[New Latin : peri- + Greek neuron, nerve; see neuron.]

per′i·neu′ri·al adj.


n, pl -neuria (-ˈnjʊərɪə)
(Anatomy) the connective tissue forming a sheath around a single bundle of nerve fibres
[C19: from New Latin, from peri- + Greek neuron nerve]
ˌperiˈneurial adj


(ˌpɛr əˈnʊər i əm, -ˈnyʊər-)

n., pl. -neu•ri•a (-ˈnʊər i ə, -ˈnyʊər-)
the sheath of connective tissue that encloses a bundle of peripheral nerve fibers.
[1835–45; < New Latin; see peri-, neur-, -ium2]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.perineurium - the sheath of connective tissue that covers a bundle of nerve fibers
connective tissue - tissue of mesodermal origin consisting of e.g. collagen fibroblasts and fatty cells; supports organs and fills spaces between them and forms tendons and ligaments
References in periodicals archive ?
In the controls and treated rats, the longitudinal sections of sciatic nerve show parallel bundles of nerve fibres encased by perineurium (Fig.
A peripheral nerve is composed of axon, myelin, endoneurium, fascicle, perineurium and epineurium.
Perineural invasion is defined as extension of tumor into the perineural plane between nerve bundles and the perineurium. For this data set, either intratumoral or extratumoral perineural invasion is regarded as a positive finding.
The spaces between the fibroblast-like cellular sheets and perineurium contained accumulated endoneurial oedema, in addition to some of the endoneurial macrophages carrying degenerated myelin (Fig.
Sural nerve biopsy demonstrated mononuclear cell infiltration, especially around the vessels and the perineurium.
The amphicrine AR42J cells were slowly inoculated (0.5 x [10.sup.6]) in the perineurium sheath of the SN of two successive groups of rats (n = 5 each) using a 25 [micro]L Hamilton[R] GASTIGHT[R] syringe, 1702LT Series (Sigma-Aldrich Chemie GmbH) and watched for 40 days.
NF-[kappa]B activation, which is involved in the pathogenesis of diabetic complications, especially DPN [104], has been identified in the endoneurium, epineurial vessels and perineurium in sural nerve biopsies of overt diabetic subjects [105].
Delayed clinical improvement prompted a biopsy and histopathological examination of the medial antebrachial nerve of the left forearm during the 7th week of illness which demonstrated an inflammatory neuropathy characterized by inflammatory changes in the endoneurium, perineurium, and epineurium.
Intraoperative findings suggested that administration of over 1 ml PRP infiltration results in pressure on the nerve fascicles in the perineurium because 1 ml of PRP infiltration causes the digital nerve width to increase to twice as large as that before injection.
It is suspected that cancer cells may reach the leptomeninges through hematogenous spread, direct invasion from parenchymal lesions, or spread along the perineurium from cranial or spinal nerves.
The clinical administration of peripheral nerve injury is still the classic epineurium or perineurium neurorrhaphy that dates back to more than 100 years ago.[2] However, efficient anastomosis of homogeneous nerve fibers in bilateral neural stumps cannot be achieved merely through these two surgical methods.