<unk>  (also<unk>  and sheath of Schwann) is the outermost layer of nerve fibers in the peripheral nervous system. It is a nucleated cytoplasmic layer of Schwann cells that surrounds the myelin sheath of axons.
Unlike the axon and the myelin sheath, the<unk>  does not degenerate after a nerve has been cut or crushed; the hollow tube formed by the<unk>  is instrumental in regenerating the nerve fiber. It is important to note that in CNS, axons are myelinated by oligodendrocytes, thus lack<unk> .
Neurolemma
Somatrem
Amnion
Ethoprophos
Libido
Triclofos
Heroic
Cholinergic