The peripheral nervous system is made up of which structures?

• A. Nerves
• B. Nerves and Ganglia
• C. Ganglia
• D. Collection of cells outside CNS

Answer: (B)

Structures in the peripheral nervous system include nerves and ganglia. The PNS comprises all neural tissue outside the brain and spinal cord, wiring the CNS to the rest of the body. Nerves are bundles of axons wrapped in connective tissue that carry impulses to and from the CNS, connecting muscles, glands, and sensory receptors. Ganglia are clusters of neuron cell bodies located outside the CNS, acting as relay or processing points, such as dorsal root ganglia for sensory input or autonomic ganglia for autonomic control. Together, nerves and ganglia capture the main structural elements of the PNS. The other options are incomplete: nerves alone miss the cell bodies contained in ganglia, ganglia alone miss the long axonal tracts, and a vague “collection of cells outside CNS” doesn't specify the organized structures that define the PNS.