" MULTIPOLAR NEURONS "
Neurons that have three or more processes attached to their cell bodies are structurally classified as multipolar. One process functions as the axon and the rest are dendrites. Both types of processes usually have many smaller branches. The vast majority of the body's neurons are located in the brain and spinal cord and most of these are multipolar in shape. The added surface area created by the branching dendrites allows approaching neurons to form more excitatory and inhibitory synapses. Multipolar neurons differ in size and shape, depending on their function and location in the CNS. For example, the following multipolar neurons are all involved in producing body movements. Even though they are classified as multipolar, notice how they differ in appearance. Pyramidal cells in the primary motor cortex execute actions planned by other areas of the brain. The long axons of the pyramidal cells carry action potentials down through the brainstem and into the spinal cord, where they synapse with motor neurons. While a movement is occurring, Purkinje cells in the cerebellum help make adjustments so it takes place as planned.