Which statement correctly describes the arrangement of gray and white matter across the brain and spinal cord?

Which statement correctly describes the arrangement of gray and white matter across the brain and spinal cord?

• A. The brain has gray outside and white inside; the spinal cord has white outside and gray inside
• B. The brain and spinal cord both have gray outside
• C. The brain has white outside and gray inside; the spinal cord has gray outside
• D. The brain has gray outside and white outside

Answer: (A)

Neural tissue organization in the CNS hinges on what gray and white matter are made of. Gray matter contains neuron cell bodies and is the site of processing; white matter contains myelinated axons that bundle and transmit signals. In the brain, processing centers sit on the outside as the cerebral cortex (gray matter), while the long-range communication pathways lie beneath it as white matter. In the spinal cord, the arrangement is reversed: the outer region is white matter filled with ascending and descending tracts, and the central area is gray matter with its dorsal and ventral horns for processing and reflexes. So the correct description is that the brain has gray matter on the outside and white matter inside, while the spinal cord has white matter on the outside and gray matter inside.

Neural tissue organization in the CNS hinges on what gray and white matter are made of. Gray matter contains neuron cell bodies and is the site of processing; white matter contains myelinated axons that bundle and transmit signals.

In the brain, processing centers sit on the outside as the cerebral cortex (gray matter), while the long-range communication pathways lie beneath it as white matter. In the spinal cord, the arrangement is reversed: the outer region is white matter filled with ascending and descending tracts, and the central area is gray matter with its dorsal and ventral horns for processing and reflexes.

So the correct description is that the brain has gray matter on the outside and white matter inside, while the spinal cord has white matter on the outside and gray matter inside.