Most of the pains that we experience result from normal nerve endings being stimulated by injury, or inflammation, or by stretching of or pressure put upon the affected parts. When, however, the nerves or the sensory tracts in the The main nerve trunk running down the spinal canal and connecting the individual’s mind and consciousness to the rest of his or her body. It is about the size of a person’s little finger, in diameter. It cannot repair itself if damaged. become damaged or disrupted by disease, then normal sensory signals become distorted and perceived as pain. Alternatively, pain pathways themselves generate pain signals in the absence of any From the Greek and meaning “around”, or away from the centre, this word refers to those parts of the nervous system that lie outside the head and spine or, more accurately, outside the brain and the spinal cord. Together they constitute the peripheral nervous system, which itself is made up of sensory nerves, nerves controlling motor functions and autonomic components. stimulus.