Neurons, also known as nerve cells, are the basic units that make up the structure and function of the nervous system. Neurons are cells with long synapses (axons), which are composed of cell bodies and cell protrusions. Cell protrusions, or cytosol, can be divided into dendrites and axons. Dendrites are a kind of cell body from the dendrites like dendrites, often a branch into two branches, branches and branches, dendrites within the protofibers and Nystrom's body; axon is a kind of cell body from the elongated protuberance, a neuron has only one axon, and the cell body connected to the conical place called the axon mound, the axon mound without Nystrom's body. Axons vary in length, with small neurons having short, thin axons and large neurons tending to have longer axons; intact axons are surrounded by a myelin sheath. Dendrites, axons and their wrapped attachments become nerve fibers, distributed in other tissues or organs on the end of the nerve fibers of tiny branches called nerve endings. There are more staining methods for neurons and nerve fibers, mainly using silver plating stain, tar violet stain, Luxol fast blue, etc.