A drawing of the three categories of neurons, based on the number of processes emanating from the cell body: unipolar, bipolar, and multipolar. Neurons generally develop as bipolar cells and then become unipolar (pseudounipolar) or multipolar. Some neuron remain bipolar, in which case the two processes may be axons (cochlear nerve & retina) or axon & dendrite (olfactory neurons). Unipolar neurons are primary sensory neurons that have their cell bodies in spinal or cranial nerve ganglia. The great majority of neurons in the body are multipolar, with several dendrites and one axon leaving the cell body. Multipolar neurons come in a variety of shapes.