Fig. 1.01. The nerve cell (neuron) consists of the nerve cell body (containing the nucleus surrounded by the perikaryon) and its processes -- usually multiple dendrites and one axon (not visible in this figure). The surface of the perikaryon and processes is covered by a plasma membrane. The interior is filled with cytoplasm and organelles. Scale = 5 µm. (Mouse, neocortex). Download the high resolution image.