How Is The Location Of Grey And White Matter Different Between The Brain And Spinal Cord?

The way the grey matter and white matter are present in the brain and the spinal cord are different. In the brain, the grey matter forms the outer layer, and is present in the cerebrum. It is the outer layer here, and it encircles the area that has the white matter. Therefore, in the brain, the grey matter is the outer layer while the white matter is the inner layer. In the spinal cord, however, the way these two kinds of matter are present is different. In the spinal cord, the white matter is present in greater quantities in the vertebrae in the upper region, i.e. those vertebrae that are closer to the brain. The grey matter is present in larger quantities in the lower vertebrae, i.e. in those vertebrae that are somewhat distal from the brain.

This difference is because of the contents of these two kinds of matter. The white matter contains axons, while the grey matter contains the cell bodies of the nerves. Proximity to the brain means more axons shooting back and forth, and distance from the brain reduces the need for more axons.