Multipolar Neurons – Tutorial
Please read Unit 5 – Introduction to Nervous System Tissues prior to completing the activities in this chapter.
Introduction to Multipolar Neurons
Multipolar neurons are large, irregularly shaped cells with a large cell body or soma and multiple cytoplasmic extensions radiating out from the cell body known as axons or dendrites. Specifically, multipolar neurons exhibit two or more dendrites which conduct action potentials toward the cell body and a single axon which conducts action potentials away from the cell body. Many images of multipolar neurons will be used to study the characteristics of multipolar neurons in this chapter; however, it will not be possible to definitively differentiate between axons and dendrites in the multipolar neurons photographed in the tutorials that follow.
Multipolar neurons are the most common type of neuron in the central nervous system and lower motor neurons that control the voluntary contraction of skeletal muscles are also multipolar neurons. The cell body of a lower motor neuron is located in the spinal cord, but its single long axon exits the spinal cord and extends out to a skeletal muscle. Once the axon reaches a muscle it forms hundreds or even thousands of terminal branches known as telodendria that control the contraction of individual skeletal muscle cells (muscle fibers).
