a cell of nerve tissue forming the membranes of the long processes of the nerve cells (axons) in the peripheral nerves and ganglia; first described by T. Schwann in 1838.
The nucleus of a Schwann’s cell is oval and contains one or two nucleoli. Masses of chromatin are found on the inner surface of the nuclear membrane. Mitochondria, lysosomes, the Golgi complex, microtubules, microfibrils, free ribosomes, and ribosomes attached to the membranes are concentrated around the nucleus in the cytoplasm. Schwann’s cells may have cilia. They act as supporting cells in the processes of nerve cells and help form (and in unusual cases destroy) myelin in the medullated fibers. Metabolites penetrate the process of a nerve cell through the substance of Schwann’s cells or at the point where the cells meet. It is possible that some substances are formed in Schwann’s cells and then proceed to the processes. The capacity of Schwann’s cells for wave like movements may be related to the transport of various substances along the processes of nerve cells.