The principles of psychology . lood-vesselsof that part into relation with the other parts of theapparatus. The cerebro-spinal nervous system, besides ha\ing thesedirect communications with the muscular walls of the tubeswhich bring blood, both to itself and to the muscles it sendsfibres to, is also put into relation with other parts onwhich it is equally, though less immediately, dependent—the viscera. These have, indeed, a nervous system of theirown, possessing apparently a considerable degree of inde-pendence—the sympathetic system; and one all-importantviscus, the heart, has a nervous syst
The principles of psychology . lood-vesselsof that part into relation with the other parts of theapparatus. The cerebro-spinal nervous system, besides ha\ing thesedirect communications with the muscular walls of the tubeswhich bring blood, both to itself and to the muscles it sendsfibres to, is also put into relation with other parts onwhich it is equally, though less immediately, dependent—the viscera. These have, indeed, a nervous system of theirown, possessing apparently a considerable degree of inde-pendence—the sympathetic system; and one all-importantviscus, the heart, has a nervous system that is demonstrablyindependent. The morphological interpretation of the vis-ceral nervous system is not settled; but whether it has aseparate origin, or belongs to the periphery of the cerebro-spinal system, the undoubted fact is that the cerebro-spinalsystem, through the nei-ves running from it into thetrunks of the sympathetic, communicates with all these vitalorgans; and that even the heart, complete as is its local. THE STRUCTURE OF THE NERVOUS SYSTESI nervous system, is, by the vagus or pneumogastric nerve,integrated witli the cerebro-spinal system. A more particular account of these and sundry structuresof the same class is not necessary here. The general fact ofsignificance for us, is, that the brain and sjiinal cord whichthrough their afferent nerves are put in relation with theactions of the external world, and Avhich through theirefferent nerves are put in relation with the structures thatreact on the external world, are also put in relation withthe organs immediately or remotely instrumental in supply-ing them with nutriment, and removing the effete mattersresulting from their activities. § 16. In the foregoing description I have endeavoured toinclude all that Psychology needs. Many conspicuoustraits of nervous structure which some will think ought tobe set down, are really altogether irrelevant. That in thespinal cord the grey matter is placed internally, w
Size: 2174px × 1150px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, bookidpri, booksubjectpsychology
