PERINEURIAL CELLS Meaning and
Definition
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Perineurial cells, also known as perineurial fibroblasts or perineurial-like cells, are specialized cells that form the perineurium in the peripheral nervous system (PNS). The perineurium is a protective connective tissue sheath surrounding nerve fascicles, which are bundles of nerve fibers in the PNS.
Perineurial cells have elongated, flat-shaped bodies with thin cytoplasmic extensions that interdigitate with neighboring perineurial cells, forming tight junctions and creating a barrier. This barrier plays a crucial role in maintaining the structural integrity and selective permeability of the nerve fascicles within the peripheral nerves.
The main function of perineurial cells is to act as a physical and biochemical barrier, regulating the transport of molecules, ions, and fluids between the blood vessels and nerves. They create a microenvironment that protects the nerve fibers from potential damage or fluctuations in the surrounding extracellular fluid.
Additionally, perineurial cells contribute to the homeostasis of the nerve fibers by secreting extracellular matrix proteins like collagen and laminin, which provide structural support and contribute to the maintenance of the specialized microenvironment within the nerves.
In certain pathological conditions, such as nerve injury or inflammation, perineurial cells can undergo changes in their morphology and function, leading to the disruption of the blood-nerve barrier and altered nerve homeostasis. Understanding their role can be crucial in understanding peripheral nerve disorders and developing potential therapeutic interventions.
Etymology of PERINEURIAL CELLS
The term "perineurial cells" has a specific etymology:
- "Peri-" is a prefix derived from Greek, meaning "around" or "surrounding".
- "Neurial" is derived from the word "neuron", which is also of Greek origin, meaning "nerve".
- Therefore, "perineurial" refers to something that is around or surrounding nerves.
When combined, "perineurial cells" refers to the specific cells that compose the perineurium, which is a connective tissue layer that surrounds and protects nerves.
