. Each pain receptor forms one end of a nerve cell neurotransmitters. It is connected to the other end in the spinal cord by a long nerve fiber or axon. When the pain receptor is activated, it sends an electrical signal up the nerve fiber
The nerve fiber. is bundled with many others to form a peripheral nerve. The electrical signal passes up the neurotransmitters within the peripheral nerve to reach the spinal cord in the neck.
Within an area of the spinal cord called the dorsal horn, the electrical signals are transmitted from one neurotransmitters to another across junctions synapses by means of chemical messengers neurotransmitters. Signals are then passed up the spinal cord to the brain.
