It is interesting to recall that some forty years ago Sherrington (1) included a description of spinal visceral reflexes in a chapter on "The Spinal Cord" which he contributed to Schafer's Text Book of Physiology. In the course of the article he drew attention to the fact that after destruction of the higher nerve centres, e.g. brain, the competence remaining to the spinal centres is found great�st for visceral reactions. From this point of view the visceral reflexes present the most per fect reactions of the spinal animal. The bulbo-spinal animal, receiving as it does the afferent impulses of the vagus as well as of the thoracic and sacral nerves, may indeed be considered as regards visceral function a fairly perfect animal. The purely spinal animal does, however, exhibit some amount of damage to the nervous regulation of its viscera; this is chiefly of the nature of "shock" and temporary.Magoun (2) rightly points out that "the full role of the auto nomic syst�m in the integration of bodily processes is only exerted through the action of essential supranuclear centres in the medulla, hypothalamus, and cerebral cortex." It should be emphasized, however, that the vis � era, though dependent on the nervous sys tem for the integration of reactions and necessary adjustments, are capable of independent function after section of the extrinsic nerves.It is intended to include in this chapter studies on the represen tation of the sympathetic and parasympathetic systems in the cerebral cortex, hypothalamus, medulla, and the s pinal cord, to gether with investigations on the autonomic nerves in their more general aspects. Papers concerned with the problem of visceral sensation, including referred pain, will also be discussed, and refer ence will be made to the viscerosomatic and somaticovisceral re flexes which seem logically to belong to this section. CENTRES Cerebral cortex.-Few papers describing the influence of the cortex on the discharge of impulses by way of the autonomic nerv ous system have appeared during the year.365 Annu. Rev. Physiol. 1944.6:365-390. Downloaded from www.annualreviews.org Access provided by University of Bath on 02/04/15. For personal use only. Quick links to online content Further ANNUAL REVIEWS