Nerves
are actually made up of many of the axons of individual nerve cells running
together towards the spinal cord to enter into the central nervous system. Pain
nerves mix with position sense nerves, temperature sense nerves, vibratory sense
nerves, and muscle control nerves. These nerves become larger and are made up
of more axons as they move closer to the spinal cord. Just before they reach
the spinal cord the nerves form a nerve root, which splits into a front and
back part (Dorsal Root). The part that goes to the back of the spinal cord carries
the pain signal to the spinal cord (Dorsal Horn of the Spinal Cord). From here
it is passed from a relatively short nerve (Interneuron) to the nerve tract
that runs to the brain (Spinothalamic Tract). When it reaches the brain it is
passed to other nerve cells that carry it over to the thinking (Cerebrum) and
emotional (Limbic System) centers of the brain.
