Preganglionic neuron nuclei are located in which regions?

Preganglionic neuron nuclei are located in which regions?

• A. Thoracolumbar, craniosacral
• B. Brainstem and cerebellum
• C. Cervical and lumbar
• D. Sacral and coccygeal

Answer: (A)

Preganglionic neurons in the autonomic system originate in two main places: the spinal cord in the thoracic and upper lumbar segments (the thoracolumbar region) for the sympathetic division, and in brainstem nuclei plus the sacral spinal cord (the craniosacral region) for the parasympathetic division. Because their cell bodies are located in these two broad areas, the correct description is thoracolumbar and craniosacral. This contrasts with options that would place preganglionic bodies only in brainstem/cerebellum, or only in other spinal regions, which don’t capture both autonomic divisions.

Preganglionic neurons in the autonomic system originate in two main places: the spinal cord in the thoracic and upper lumbar segments (the thoracolumbar region) for the sympathetic division, and in brainstem nuclei plus the sacral spinal cord (the craniosacral region) for the parasympathetic division. Because their cell bodies are located in these two broad areas, the correct description is thoracolumbar and craniosacral. This contrasts with options that would place preganglionic bodies only in brainstem/cerebellum, or only in other spinal regions, which don’t capture both autonomic divisions.