When nerve signals transmitted to a cell and brain volume to a level that makes it sensitive to stimulation. Will cause the response to pain perception pain.
When the nerve signals that are sent through to the t-cells and the brain have reached levels that make sensitive information between tun will cause a response to pain, back pain recognition.
When the signal is sent through the optic nerve to the brain cells and it has a lot of make up to a level that will be sensitive to the stimulus to the response to the pain after the perceived pain