Which tissue sample represents part of the central nervous system?

• A. Brain
• B. Spinal cord
• C. Nerve
• D. Ganglion

Answer: (B)

In the nervous system, the central nervous system consists of the brain and spinal cord, while the peripheral nervous system includes nerves and ganglia. The spinal cord is a CNS tissue because it lies within the vertebral column and contains the classic CNS organization of gray matter with neuron cell bodies and white matter with myelinated axons, all enclosed by the meningeal coverings. In contrast, a nerve is a peripheral bundle of axons, and a ganglion is a peripheral collection of neuronal cell bodies. So the tissue most representative of the central nervous system among the options is the spinal cord.