Treatments for severe pain going back to the spinal cord and brain. Increased painful nerve impulses from the cutaneous, muscular, articular or visceral tissues from the nociceptors, in yellow to the spinal cord, then red to the cerebral cortex via the medulla oblongata and the mesencephalon of the brainstem seen in horizontal cuts. Inibition by descending routes in pink. zoom on the enkephalin neuron of the spinal cord in blue and the opiate receptors on the neuron jaunereceptor opiate morphine morphine enkephalinergic neuron enkephalin substance P spinal cord bulge midbrain thalamus brain severe pain neurology drawing health sciences