they surround the nerves in the peripheral nervous system to provide a myelin sheath that makes nerve signals run faster. these are different from oligodendrocytes because they don't branch and they aren't found in the central nervous system.
Function. One of the most important functions of the Schwann cell is to myelinate the axons of the PNS. Myelin, which is a fatty layer that insulates the axon, helps to increase the saltatory conduction of the neuron. A myelinating Schwann cell wraps around a single axon.
