What are the two autonomic LMN called?

• A. Preganglionic and postganglionic
• B. Central and peripheral
• C. Afferent and efferent
• D. Primary and secondary

Answer: (A)

In the autonomic motor system, the signal to an organ travels through two neurons in sequence. The first is the preganglionic neuron, with its cell body in the brainstem or spinal cord, whose axon goes to an autonomic ganglion. There it forms a synapse with the second neuron, the postganglionic neuron, whose cell body sits in the ganglion and whose axon extends to the target tissue. This two-neuron chain is why we refer to preganglionic and postganglionic as the autonomic lower motor neurons. The other descriptors don’t fit because central/peripheral describe location in the nervous system, and afferent/efferent describe sensory versus motor flow, not the two-neuron arrangement itself.