Mena. Mena was founded in 1896 as a railroad town at the eastern foot of Arkansas's second highest peak, Rich Mountain (elev. 2,681).It is the eastern terminus of the Talimena Scenic Drive, a 54-mile byway that travels the crests of Rich and Winding Stair mountains between Mena and Talihina, Oklahoma.he byway and park provide impressive vistas of the Ouachita Mountains. The Mena Depot Center, located in a restored 1920 railroad depot, greets the town's visitors with tourism information, art and local history exhibits and railroad memorabilia. In Janssen Park, stands an 1851 log cabin still on its original site.
Structure [edit]. Schwann cells are a variety of glial cell that keep peripheral nerve fibres (both myelinated and unmyelinated) alive. In myelinated axons, Schwann cells form the myelin sheath (see above). The sheath is not continuous.Individual myelinating Schwann cells cover about 100 micrometres of an axonâequating to approximately 10,000 Schwann cells along a 1 metre length of the axon.n this sense, Schwann cells are the peripheral nervous system's analogues of the central nervous system 's oligodendrocytes. However, unlike oligodendrocytes, each myelinating Schwann cell provides insulation to only one axon (see image).
Schwann cells: these cells provide the myelin that covers neurons in the peripheral nervous system. Larger neurons are covered in a myelin sheath. Myelin is high in lipid and serves the same purpose as insulation around electrical wires.Myelinated axons conduct nerve impulses faster.hese cells form the substance of the brain, spinal cord, and peripheral nervous system. The brain is composed of the basic units of the cerebral hemispheres, brainstem, and cerebellum. The cerebral hemispheres can be further categorized by structure and function.