neuron A grayish or reddish granular cell with specialized processes that is the fundamental functional unit of nervous tissue. Tomasz Adamusiak James Malone The basic cellular unit of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system. The basic cellular units of nervous tissue. Neurons are polarized cells with defined regions consisting of the cell body, an axon, and dendrites, although some types of neurons lack axons or dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system. NIFSTD:sao1417703748 NCIt:C12623 SNOMEDCT:47220008 cell type