First, lets distinguish between
nervous system functioning in acute and chronic pain situations. For an overall image of the relationship of these 2 types of pain, you can think of acute pain as fast and chronic pain as slow. The speed of the pain is based on the speed of transmission of the communication signals from the origination site to the brain. Acute pain signals are communicated to the brain along different
nerves than are chronic pain signals. Acute pain is like traveling in a souped up racecar, while chronic pain is a ride in the old clunker. Both types of nerve fibers travel on the spinothalamic tract, the main freeway for nerve fibers that communicate pain to the brain.