. A text-book of comparative physiology [microform] : for students and practitioners of comparative (veterinary) medicine. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. THE SPINAL ^BNERAL. 4«7 tide be allowed to hang in the dilute add, it will be withdrawn. 4. If a small piece of blotting-paper dipped in the acid be placed on the thigh, and the leg of that side gentl;^ held, the other may be drawn up and remove the object It may be noticed that in every case a certain interval of time elapses before the result follows. Upon increasing the
. A text-book of comparative physiology [microform] : for students and practitioners of comparative (veterinary) medicine. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. THE SPINAL ^BNERAL. 4«7 tide be allowed to hang in the dilute add, it will be withdrawn. 4. If a small piece of blotting-paper dipped in the acid be placed on the thigh, and the leg of that side gentl;^ held, the other may be drawn up and remove the object It may be noticed that in every case a certain interval of time elapses before the result follows. Upon increasing the strength of the acid very much this interval is shortened, and the number of groups of muscles called into ncUon ia increased. - Again, the result is not the same in all respects when the nerve of the 1^ is directly stimulated, as when the skin first receives the impression. Section of the nerves of the parts abolishes these effects; so also does destruction of the spinal cord, or the part of it with which the nerves of the looalitiea stimulated are connected; and more exact experiments show that in the ab- sence of the gray matter the section of the posterior or anterior roots of the nerves also renders such manifestations as we have been describing impossible. These experiments and others seem to show that an afferent nerve, an efferent nerve, and one or more central cells are necessary for a reflex action; that the latter is only a perfectly' co-ordinated one when the skin (end-organs) and not the nerve- trunks are stimulated; that' there is a latent period of stimula- tion, suggesting a central "summation" of impulses necessary for the effect; th|it the reflex is not due to the mere passage of impulses from an afferent to an efferent nerve through the ccnd, but implies important processes in the central cells them- selves. The latter is made further evident from the fact that (1) strychnia greatly alters reflex action 1^ shortening the latent period and extend
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Keywords: ., bookauthormillswes, bookcentury1800, bookdecade1890, bookyear1890
