Polyneuritis is defined as a disorder that affects which anatomical structures?

• A. Central nervous system
• B. Peripheral nerves
• C. Autonomic nervous system only
• D. Spinal cord

Answer: (B)

Polyneuritis is an inflammation that involves multiple nerves in the peripheral nervous system. The peripheral nerves are the network outside the brain and spinal cord that carry motor, sensory, and autonomic signals to and from the body. When several of these nerves become inflamed, you get widespread symptoms like weakness and sensory changes in different areas. Problems limited to the brain or spinal cord are issues of the central nervous system, not polyneuritis. Autonomic fibers can be involved as part of the peripheral nerves, but the defining feature is inflammation of several peripheral nerves rather than the autonomic system alone.