SPINE, Pathological Changes in. The odontoid process of the axis of the spine pre sents two articulating surfaces, one in front, of an oval form, for articulating with the atlas, and another for the transverse ligament, the latter frequently encroaching on the sides of the process. Serious displacement at this point of articulation causes instant death, due to pres sure and injury of the cord and nerve-trunks. The vertebral column quite frequently sustains fracture from an indirect violence which tends to produce overexertion on one flexion of its normal curvature. Tuberculosis of the ver tebral articulations or Pott's disease is an af tection of the spine. At birth there are no curves in the infant's spine, but as the child as sumes the sitting or erect posture, curves which are recognized as the normal vertebral curves are developed. Weak muscles, careless pos tures and paralysis of special groups of spinal muscles arc causes of spinal curvature. Scolio sis is lateral curvature, that is, with the convex ity of the curve to one side. Cyphosis, or
humpback, is the form in which the convexity of the column is increased in a posterior direc tion. Lordosis, or hollow-back, is a spinal de viation in which the convexity of the curve is forward. In old age the spine is apt to shorten owing to shrinking of the gristly for mation between the vertebra. Inflammation of the cord rarely gives rise to pus, hut a few cases have been described. The suppuration is necessarily micro-organismal in origin and as a rule it is either due to some septicemia or trau matism, or secondary to purulent meningitis. The spinal cord (q.v.) is influenced by diseased conditions of other parts of the body. It is the centre for all the degenerative disorders of the nervous system, such as locomotor ataxia, degenerative spastic paraplegia, primary lateral sclerosis; etc. The chiropractics have made special study of the spine and the nerves pass ing through its articulations. See CHIRO