Schwann cells

A peripheral nerve, cut in cross section, shows numerous axons of various sizes surrounded by myelin sheaths. The myelin sheath is produced by Schwann cells in the peripheral nervous system. Schwann cell cytoplasm is visible around each sheath and an occasional Schwann cell nucleus is present. Endoneurium surrounds each sheath. 1000x

A myelin sheath surrounds an individual axon and consists of the spiral wrappings of a Schwann cell plasma membrane. The uniquely high lipid content of myelin provided by the plasma membrane insulates the axon and increases conduction velocity. The radial lines in the sheath are proteinaceous remnants of the plasma membrane. Endoneurium surrounds the Schwann cells.

A myelin sheath surrounds an individual axon and consists of the spiral wrappings of a Schwann cell plasma membrane. The uniquely high lipid content of myelin provided by the plasma membrane insulates the axon and increases conduction velocity. The radial lines in the sheath are proteinaceous remnants of the plasma membrane. Endoneurium surrounds the Schwann cells.

A myelin sheath surrounds an individual axon and consists of the spiral wrappings of a Schwann cell plasma membrane. The uniquely high lipid content of myelin provided by the plasma membrane insulates the axon and increases conduction velocity. The radial lines in the sheath are proteinaceous remnants of the plasma membrane. Endoneurium surrounds the Schwann cells.

The next image is similar to that outlined by the rectangle seen by electron microscopy.