<Tr> <Th> FMA </Th> <Td> 5867 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> A motor neuron (or motoneuron) is a neuron whose cell body is located in the spinal cord and whose fiber (axon) projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands . Motor neurons' axons are efferent nerve fibers that carry signals from the spinal cord to the effectors to produce effects . Types of motor neurons are alpha motor neurons, beta motor neurons, and gamma motor neurons . </P> <P> There are upper motor neurons and lower motor neurons, with the cell type described above being a lower motor neuron . Upper motor neurons are cortico - spinal interneurons that arise from the motor cortex and descend to the spinal cord where they activate the lower motor neurons through synapses . The term' motor neuron' is usually restricted to the efferent nerves that actually innervate muscles (the lower motor neurons). </P>

What is the main function of motor neurons