ABSTRACT
Introduction T he spinal level includes the vertebral column and its contents. T he spinal canal within the vertebral column is the passage formed by the vertebrae. It extends from the foramen magnum of the skull through the sacrum of the spinal column and contains the spinal cord, nerve roots, spinal nerves, meninges, and the vascular supply of the spinal cord. Five o f the major systems are represent ed in the spinal canal: the sensory, motor, internal regu lation, vascular, and cerebrospinal fluid systems.The vas cular and cerebrospinal fluid structures are the support systems o f the spinal cord. Diseases o f the spinal canal involve one or more of these systems and produce patterns of disease distinctive to this level. The anatomical and phys iologic characteristics of the spinal cord and spinal nerves that permit the identification and localization o f diseases in the spinal canal are presented in this chapter.
