Definition
Schwann cells are specialized glial cells that support nerve fibers in the peripheral nervous system. They form the myelin sheath, a fatty insulation around axons, increasing the speed of nerve signal transmission. Think of them as tiny construction workers, wrapping layers of insulation around electrical wires. Each Schwann cell myelinates only one segment of an axon. This contrasts with oligodendrocytes in the central nervous system. They also aid in nerve regeneration by forming a regeneration tube. Without Schwann cells, nerve signals would travel much slower.