Deep somatic pain must get from the site of an injury or illness to your brain in order for you to react. This is the job of the nervous system. When an injury happens, a structure in your body called a pain receptor is activated, and an electrical message is created. This message is passed from the pain receptor, to nerves in the area of the injury, to the spinal cord, and finally, to the brain. Your brain then senses the pain so you can react.