Nervous_System

Nervous System THE NERVOUS SYSTEM is the most complicated and highly organized of the various systems which make up the human body. It is the mechanism concerned with the correlation and integration of various bodily processes and the reactions and adjustments of the organism to its environment. In addition the cerebral cortex is concerned with conscious life. It may be divided into two parts, central and peripheral. The central nervous system consists of the encephalon or brain, contained within the cranium, and the medulla spinalis or spinal cord, lodged in the vertebral canal; the two portions are continuous with one another at the level of the upper border of the atlas vertebra. The peripheral nervous system consists of a series of nerves by which the central nervous system is connected with the various tissues of the body. For descriptive purposes these nerves may be arranged in two groups, cerebrospinal and sympathetic, the arrangement, however, being an arbitrary one, since the two groups are intimately connected and closely intermingled. Both the cerebrospinal and sympathetic nerves have nuclei of origin (the somatic efferent and sympathetic efferent) as well as nuclei of termination (somatic afferent and sympathetic afferent) in the central nervous system. The cerebrospinal nerves cells, nerve, nervous, nerves, spinalis, processes, medulla, ganglia, brain, sympathetic, substance, fibers, spinal, system, fig, central, two, found, various, peripheral, one, neuroglia, gray, body, white, viscera, tissues, tissue, portions, groups, efferent, consists, connected, cerebrospinal, cell