Perineurium Information & Perineurium Links at HealthHaven.com

Perineurium
	Transverse section of human tibial nerve. (Perineurium labeled at upper right.)
	Nerve structure
Gray's	subject #183 728
MeSH	Perineurium

In the spinal cord, nerve fibers are each wrapped in a protective sheath known as the endoneurium. These are bundled together into groups known as fascicles, each surrounded by a protective sheath known as the perineurium. Several fascicles may be in turn bundled together with a blood supply and fatty tissue within yet another sheath, the epineurium. This grouping structure is analogous to the muscular organization system of epimysium, perimysium and endomysium.

The perineurium is composed of connective tissue, which has a distinctly lamellar arrangement consisting of roughly 7-8 concentric layers. The perineurium is cellular, and is composed of perineurial cells, which are epithelioid myofibroblasts. Perineurial cells are sometimes referred to as myoepithelioid due to their epithelioid and myofibroblastoid properties including tight junctions, gap junctions, external laminae and contractility.

The perineurium is a smooth, transparent tubular membrane which may be easily separated from the fibers it encloses. In contrast, the epineurium is a tough and mechanically resistant tissue which is not easily penetrated by a needle.

[edit] External links

Perineurium at eMedicine Dictionary
Histology at OU 1_03 - "Peripheral nerve"
Organology at UC Davis nervous/pns/nerve1/nerve2 - "PNS, nerve (LM, Low)"
Histology at BU 21401loa
Diagram at Howard
Histology at ucla.edu

This neuroscience article is a stub. You can help Wikipedia by expanding it.