the cells that surround an axon creating a myelin sheath in the pns are called
Myelin Schwann cells supply the myelin for the peripheral nervous system, whereas oligodendrocytes, specifically of the interfascicular type, myelinate the axons of the central nervous system. Myelin is considered a defining characteristic of the (gnathostome) vertebrates, but myelin-like sheaths have also been seen in some invertebrates, although they are quite different from vertebrate myelin at molecular level. Myelin was discovered in 1854 by Rudolf Virchow.[2]