Which part of the nervous system features a chain of ganglia adjacent to the spine?

• A. Sympathetic nervous system
• B. Parasympathetic nervous system
• C. Central nervous system
• D. Enteric nervous system

Answer: (A)

A chain of ganglia adjacent to the spine is a hallmark feature of the sympathetic division of the autonomic nervous system. This structure, the sympathetic trunk or paravertebral ganglia, runs on either side of the vertebral column from the base of the skull down to the coccyx. Preganglionic neurons originate in the thoracic and upper lumbar spinal segments and send fibers into this chain where they typically synapse with postganglionic neurons; the postganglionic fibers then travel to target organs, enabling a rapid, coordinated fight-or-flight response. In contrast, the parasympathetic system has ganglia located near or within the target organs rather than in a long chain beside the spine. The central nervous system comprises the brain and spinal cord and does not contain peripheral ganglia, and the enteric nervous system operates mainly within the gut wall as an intrinsic network, not a spine-adjacent ganglion chain.