Animation of the main nerve pathways in the human brain. These nerve pathways link different regions of the brain, and are known as the white matter. The pathways are made up of the myelinated axons of nerve cells, whose bodies are generally found in the grey matter, which forms the outer parts of the brain. In general, grey matter is responsible for processing and generating signals, and white matter for conveying signals to where they are required. The brain receives signals from the body through the brainstem, which connects to the spinal cord. The separation between the two hemispheres is also clear here, and they are linked only by a narrow belt of fibres, the corpus callosum. Master has a transparent alpha channel. See clips K004 5003 and 5004 for the clip on a white and black background respectively.