scholarly journals On the relation which subsists between the nervous and muscular systems in the more perfect animals, and the nature of the influence by which it is maintained

1837 ◽  
Vol 3 ◽  
pp. 164-165
Keyword(s):  
Nervous System ◽  
Royal Society ◽  
Spinal Marrow ◽  
Chemical Agents ◽  
The Subject ◽  
The Brain ◽  
Mechanical Irritation ◽  
Nervous Influence

The author, after referring to his former papers which have at different times been read to the Royal Society, and published in their Transactions, is led to view the brain and spinal marrow as the only active parts of the nervous system 3 the nerves, whether belonging to the class of cerebral or ganglionic, together with their plexuses and ganglions, serving only as the means of conveying and combining the various parts of the former organs, and therefore being passive with reference to their functions. This view of the subject is directly opposed to that which has been adopted by many physiologists, who consider these ganglions as the sources, and not the mere vehicles, of nervous influence. In order to determine this point, the author made the following experiment on an animal that had been pithed so as to destroy its sensibility, while the action of the heart continued. Under these circumstances, he applied mechanical irritation, and also various chemical agents, to the ganglions and plexuses of the ganglionic nerves, and found that the heart continued to beat with the same regularity as before, and with the same frequency of pulsation.

VI. Experiments made with a view to ascertain the principle on which the action of the heart depends, and the relation which subsists between that organ and the nervous system

1815 ◽  
Vol 105 ◽  
pp. 65-90 ◽  
Keyword(s):  
Nervous System ◽  
The Body ◽  
The Other ◽  
Modus Operandi ◽  
Spinal Marrow ◽  
Difference Of Opinion ◽  
The Subject ◽  
The Brain ◽  
General Opinion ◽  
Nervous Influence

The following experiments were begun with a view to as­ certain the manner in which certain poisons act in destroying life. I soon found that, in order to make any considerable progress in such an inquiry, it is necessary to ascertain how far the powers of the nervous and sanguiferous systems di­rectly depend on each other. There seems never to have been any difference of opinion respecting the direct depend­ence of the nervous on the sanguiferous system. When the powers of circulation are increased or diminished, the nervous system always suffers a corresponding change, nor can the latter, under any circumstances, continue to perform its functions after the former are destroyed. I speak of the warm blooded animals. In cold blooded animals the process of dying is so slow, that the functions of the nervous system abate very gradually, after the circulation has wholly ceased. The converse of the above proposition is by no means so generally admitted. It is evident that certain changes of the nervous, produce corresponding changes in the sanguiferous, system ; yet, while some assert, that the action of the heart depends as immediately on the brain, as that of the latter does on the heart, others maintain, that the nervous power may be wholly destroyed without impairing the vigour of this organ. This point it is necessary to determine, before we can trace with precision the modus operandi of poisons. The following inquiry therefore may be divided into two parts. In the first, I shall endeavour to ascertain how far the power of the heart is influenced by the state of the nervous system; in the other, by what steps certain poisons destroy the powers of both. This I shall reserve for another paper, and here confine my­self to the first part of the subject. Till the time of Haller, it seems to have been the general opinion, that the muscles derive their power from the nervous system. He taught, that the power of the muscles depends on their mechanism, that the nervous influence is merely a stimulus which calls it into action, and consequently that those muscles, the heart for example, which act only by the appli­cation of one peculiar stimulus, unconnected with the nervous system, are wholly independent of it. This opinion seemed confirmed by its being generally admitted, that the action of the heart continues after it is removed from the body, and that it cannot be influenced by stimulating the brain, or spinal marrow, or the nerves which terminate in it. Haller and his followers maintain, that there are two distinct vital powers, one of the nervous and another of the sanguiferous system.

scholarly journals XIV.—Of the Fourth and Sixth Nerves of the Brain;—being the concluding paper on the distinctions of the Nerves of the Encephalon and Spinal Marrow

1839 ◽  
Vol 14 (1) ◽  
pp. 237-241 ◽  
Author(s):  
Charles Bell
Keyword(s):  
Optic Nerve ◽  
Royal Society ◽  
Circular Muscle ◽  
Complex Nature ◽  
Spinal Marrow ◽  
The Subject ◽  
The Brain ◽  
Royal Society Of London

Interesting as theoptical properties of the eye have been to philosophers in every age, there are conditions of this organ which are no less curious, and which have not had their share of attention.In the year 1823, I introduced the subject to the Royal Society of London, nearly in the terms I am now using, but there is much more in the subject than I then conceived, although I see no reason to change the mode of contemplating it.The eight muscles of the eye, and the five nerves, exclusive of the optic nerve, which pass to them, imply the complex nature of the apparatus exterior to the globe, and I fear it is too plain that the subject has not been satisfactorily treated.It is chiefly with respect to the protecting motions of the eye that the difficulty occurs, for I hope the dependence of the proper organ of vision on the voluntary muscles of the eye, has been proved and acknowledged.Permit me to draw the attention of the Society to what appears a very simple piece of anatomy, the circular muscle which closes the eyelids, orbicularis palpebrarum.

XIII. On the nervous system

1840 ◽  
Vol 130 ◽  
pp. 245-254 ◽  
Keyword(s):  
Nervous System ◽  
Medical Profession ◽  
Spinal Marrow ◽  
Long Period ◽  
The Subject ◽  
Short Essay ◽  
The Brain

Twenty years have passed since the Society honoured me by printing my first paper on the functions of the nervous system. It is thirty years since I circulated a short essay, in which the idea of the new principle which has guided me in my inqui­ries into this subject was pointed out. The Society will acknowledge that since that time, investigations into the nervous system have been prosecuted with a success strongly in contrast with that attending the inquiries during the long period of some hundred years, in which a false hypothesis had satisfied the minds of the medical profession, and chained down physiologists in inactivity. In 1821 I had made so much progress in these investigations, that I was encouraged to present my first paper to the Society, as no longer the expression of mere opinions founded on experiments too delicate to be generally appreciated, but demonstrations of substantial facts, easily proved to be correct, and such as the Society has always sought to encourage. After the principle had been once established by anatomy and experiment, that the nerves possess distinct functions in correspondence with their origins from the brain and spinal marrow, time and opportunity were alone wanting for collecting the pathological facts which were to give importance to the observations in these early papers. Those facts I am now desirous of placing before the Society, to complete the subject as far as regards my own labours.

Researches into the effects of certain physical and chemical agents on the nervous system

1851 ◽  
Vol 5 ◽  
pp. 667-668
Keyword(s):  
Nervous System ◽  
Electric Current ◽  
Mechanical Injury ◽  
The Body ◽  
The Other ◽  
Hydrocyanic Acid ◽  
Spinal Marrow ◽  
Chemical Agents ◽  
The Subject ◽  
Physical And Chemical

The professed object of the author, in the present paper, is “ to detail the results of an investigation of the phenomena and the laws of production and action of certain secondary or induced conditions of the nervous system, which are effected by a voltaic, and proba­bly by any other electric current, but persistent after the influence of that current is withdrawn.” This condition he designates by the new term electrogenic , as describing at once the origin and the independence of that condition. On the present occasion he confines himself to the subject of the electrogenic condition of the muscular nerves, postponing to future inquiries that of the incident nerves and of the spinal marrow; and also the modes of action of other physical and chemical agents, such as mechanical injury, heat and cold, strychnine, and the hydrocyanic acid. The bones and muscles of the brachial lumbar and pelvic regions of a frog, being isolated from all the other parts of the body, except­ing only by means of their respective brachial and lumbar nerves, which were perfectly denuded on all sides, and raised from the glass on which the limbs were laid, a voltaic current from a pair of the “couronne de tasses” was passed downwards through the nerves, in a direction from their origin in the spinal marrow towards their ter­minations in the muscles. Energetic muscular movements were at first excited; and the current was thus continued during the space of five, ten, or fifteen minutes, and at the end of this period was withdrawn. No sooner was the current discontinued than the mus­cles were affected with spasmodic contractions, and with a tetanoid rigidity, constituting the secondary, or what the author denominates the electrogenic condition ; an effect, which as instantly subsides on the restoration of the voltaic current.

On the function of the medulla oblongata and medulla spinalis, and on the excito-motory system of nerves

1837 ◽  
Vol 3 ◽  
pp. 463-464
Keyword(s):  
Nervous System ◽  
Medulla Oblongata ◽  
Special Function ◽  
Intercostal Nerve ◽  
Muscular System ◽  
Spinal Marrow ◽  
Pathological Conditions ◽  
Motor Nerves ◽  
The Brain ◽  
Nervous Influence

The author begins by observing that a former memoir of his, entitled, “ On the Reflex Function of the Medulla Oblongata and Medulla Spinalis,” published in the Philosophical Transactions for 1833, has been translated into German, and favourably spoken of by Professor Muller, of Berlin. He states that his object in the present paper is to unfold what he calls a great principle in physiology j namely, that of the special function, and the physiological and pathological action and reactions of the true spinal marrow, and of the excito-motory nerves. The two experiments which he regards as affording the type of those physiological phenomena and pathological conditions, which are the direct effects of causes acting in the spinal marrow, or in the course of the motor nerves, are the following :— 1. If a muscular nerve be stimulated, either mechanically by the forceps, or by means of galvanism passed transversely across its fibres, the muscle or muscles to which it is distributed are excited to contract.—2. The same result is obtained when the spinal marrow itself is subjected to the agency of a mechanical or galvanic stimulus. The following experiment, on the other hand, presents the type of all the actions of the reflex function of the spinal marrow, and of the excito-motory system of nerves, and of an exclusive series of physiological and pathological phenomena :—If in a turtle, from which the head and sternum have been removed, we lay bare the sixth or seventh intercostal nerve, and stimulate it either by means of the forceps or galvanism, both the anterior and posterior fins, with the tail, are immediately moved with energy. Hence the author infers the existence: 1st, of a true spinal marrow, physiologically distinct from the chord of intra-spinal nerves; 2ndly, of a system of excito-motory nerves, physiologically distinct from the sentient and voluntary nerves; and, 3rdly, of currents of nervous influence, incident, upwards, downwards, and reflex with regard to the spinal marrow. A review is then taken of the labours of preceding physiologists relative to the functions of the nervous system : in which the author criticises the reasonings of Whytt, Legallois, Mr. Mayo, Dr. Alison, and Professor Muller; and illustrates his own peculiar views by several experiments and pathological observations, which appear to him to show that muscular movements may occur, under circumstances implying the cessation of sensation, volition, and every other function of the brain; and that these phenomena are explicable only on the hypothesis that impressions made on a certain set of nerves, which he terms excitomotory , are conveyed to a particular portion of the spinal marrow belonging to that system, and are thence reflected, by means of certain motor nerves, upon certain sets of muscles, inducing certain actions. The same actions may also be the result of impressions made directly either on the spinal marrow or on the motor nerves. He accordingly considers that the whole nervous system may be divided into,— 1st, the cerebral , or the sentient and voluntary; 2ndly, the true spinal, or the excitor and motor; and, 3rdly, the ganglionic, or the nutrient, the secretory. The excito-motory system presides over ingestion and exclusion, retention and egestion, and over the orifices and sphincters of the animal frame: it is therefore the nervous system of respiration, deglutition, &c., and the source of tone in the whole muscular system. The true spinal system is the seat or nervous agent of the appetites and passions, but is also susceptible of modification by volition. This theory he proceeds to apply to the explanation of several phenomena relating to the motions of the eyelids, pharynx, cardia, larynx, muscles of inspiration, sphincter animal expulsors of the faeces and semen, to the tone of the muscular system generally, and to actions resulting from the passions. Lastly, he considers its application to various diseased states of the same functions, as manifested in cynic spasm, vomiting, asthma, tenesmus, strangury, crowing inspiration, convulsions, epilepsy, tetanus, hydrophobia, and paralysis.

scholarly journals V. A letter on a canal in the medulla spinalis of some quadrupeds

1809 ◽  
Vol 99 ◽  
pp. 146-147
Keyword(s):  
Royal Society ◽  
Human Subject ◽  
Cauda Equina ◽  
The Other ◽  
Small Stream ◽  
Spinal Marrow ◽  
The Brain ◽  
Contrary Direction

Sir, According to your request, I send you an account of the facts I have ascertained, respecting a canal I discovered in the year 1803, in the medulla spinalis of the horse, bullock, sheep, hog, and dog; and should it appear to you deserving of being laid before the Royal Society, I shall feel myself particularly obliged, by having so great an honour conferred upon me. Upon tracing the sixth ventricle of the brain, which corresponds to the fourth in the human subject, to its apparent termination, the calamus scriptorius, I perceived the appearance of a canal, continuing by a direct course into the centre of the spinal marrow. To ascertain with accuracy whether such structure existed throughout its whole length, I made sections of the spinal marrow at different distances from the brain, and found that each divided portion exhibited an orifice with a diameter sufficient to admit a large sized pin; from which a small quantity of transparent colourless fluid issued, like that contained in the ventricles of the brain. The canal is lined by a membrane resembling the tunica arachnoidea, and is situated above the fissure of the medulla, being separated by a medullary layer: it is most easily distinguished where the large nerves are given off in the bend of the neck and sacrum, imperceptibly terminating in the cauda equina. Having satisfactorily ascertained its existence through the whole length of the spinal marrow, my next object was to discover whether it was a continued tube from one extremity to the other: this was most decidedly proved, by dividing the spinal marrow through the middle, and pouring mercury into the orifice where the canal was cut across, it passed in a small stream, with equal facility towards the brain (into which it entered), or in a contrary direction to where the spinal marrow terminates.

Lantern Demonstration of Gross Lesions of the Cerebrum

1901 ◽  
Vol 47 (199) ◽  
pp. 729-737 ◽  
Author(s):  
Joseph Shaw Bolton
Keyword(s):  
Cerebral Cortex ◽  
Dura Mater ◽  
Royal Society ◽  
Mental Disease ◽  
Post Mortem ◽  
Pyramidal Layer ◽  
Gross Lesions ◽  
The Subject ◽  
The Brain ◽  
Morbid Conditions

This demonstration was a further report on the subject laid before the Association at the meeting at Claybury in February last, viz., the morbid changes occurring in the brain and other intra-cranial contents in amentia and dementia. In a paper read before the Royal Society in the spring of 1900, and subsequently published in the Philosophical Transactions, it was stated, as the result of a systematic micrometric examination of the visuo-sensory (primary visual) and visuo-psychic (lower associational) regions of the cerebral cortex, that the depth of the pyramidal layer of nerve-cells varies with the amentia or dementia existing in the patient. At the meeting of the Association referred to it was further shown, from an analysis, clinical and pathological, of 121 cases of insanity which appeared consecutively in the post-mortem room at Claybury, that the morbid conditions inside the skull-cap in insanity, viz., abnormalities in the dura mater, the pia arachnoid, the ependyma and intra-cranial fluid, etc., are the accompaniments of and vary in degree with dementia alone, and are independent of the duration of the mental disease. Since that date the pre-frontal (higher associational) region has been systematically examined in nineteen cases, viz., normal persons and normal aments (infants), and cases of amentia, of chronic and recurrent insanity without appreciable dementia, and of dementia, and the results obtained form the subject of the present demonstration. A paper on the whole subject will shortly be published in the Archives of the Claybury Laboratory.

The Pathology of Milkiness, Thickening, and Opacity of the Pia-arachnoid in the Insane

1895 ◽  
Vol 41 (175) ◽  
pp. 622-635
Author(s):  
W. F. Robertson
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Structural Changes ◽  
Brain Cortex ◽  
Mental Disease ◽  
Waste Products ◽  
The Central Nervous System ◽  
The Subject ◽  
The Brain

There is at the present time great need of more complete and definite knowledge as to the pathology of the very marked structural changes that so commonly affect the pia-arachnoid in the insane. The subject is one of much importance to all of us as medical psychologists, for not only is the condition in question one of the most conspicuous lesions associated with mental disease, but it implicates a structure of primary importance in the economy of the central nervous system. It is by way of vessels that course through this membrane that nutriment is conveyed to the brain cortex, and the waste products resulting from metabolism in the cerebral tissues are mainly conveyed away in the fluid that circulates in its lymph spaces. Therefore it is evident that these morbid changes may very seriously interfere with the functions both of nutrition and excretion in the brain.

On the reflex function of the medulla oblongata and spinalis, or the principle of tone in the muscular system

1837 ◽  
Vol 3 ◽  
pp. 210-210
Keyword(s):  
Nervous System ◽  
Medulla Oblongata ◽  
Hydrocyanic Acid ◽  
Muscular System ◽  
Spinal Marrow ◽  
Reflex Action ◽  
The Will ◽  
The Brain ◽  
Morbid State

The author, after commenting on the opinions of Le Gallois and Cruveilhier relating to the functions of the spinal marrow, adverts to a property or function of the medulla oblongata and spinalis, which he considers as having escaped the notice of these and all other physiologists; namely, that by which an impression made upon the extremities of certain nerves is conveyed to these two portions of the nervous system, and reflected along other nerves to parts different from those which received the impression. He distinguishes muscular actions into three kinds: first, those directly consequent on volition; secondly, those which are involuntary, and dependent on simple irritability; and thirdly, those resulting from the reflex action above described, and which include those of the sphincter muscles, the tonic condition of the muscles in general, the acts of deglutition, of respiration, and many motions, which, under other circumstances, are under the guidance of the will. Volition ceases when the head or brain is removed; yet, as he shows by various experiments, movements may be then excited in the muscles of the limbs and trunk, by irritations applied to the extremities of the nerves which remain in communication with the spinal marrow: but these actions cease as soon as the spinal marrow is destroyed. Hence the author concludes that they are the effect of the reflex Action of the spinal marrow, which exists independently of the brain; and, indeed, exists in each part of the organ independently of every other part. He considers that this reflex function is capable of exaltation by certain agents, such as opium and strychnine, which in frogs produce a tetanic and highly excitable state of muscular irritability. Hence he is led to view the reflex function as the principle of tone in the muscular system. He considers that certain poisons, such as the hydrocyanic acid, act by destroying this particular function. The effects of dentition, of alvine irritation, and of hydrophobia, of sneezing, coughing, vomiting, tenesmus, &c. &c., are adduced as exemplifications of the operation of the same principle when in a morbid state of exaltation.

scholarly journals II. The Croonian Lecture, on some physiological researches, respecting the influence of the brain on the action of the heart, and on the generation of animal heat

1811 ◽  
Vol 101 ◽  
pp. 36-48 ◽  
Keyword(s):  
Blood Vessels ◽  
Royal Society ◽  
Spinal Marrow ◽  
Animal Body ◽  
The Brain

Having had the honour of being appointed, by the President of the Royal Society, to give the Croonian Lecture, I trust that the following facts and observations will be considered as tend­ing sufficiently to promote the objects, for which the Lecture was instituted. They appear to throw some light on the mode, in which the influence of the brain is necessary to the conti­nuance of the action of the heart; and on the effect, which the changes produced on the blood in respiration have on the heat of the animal body. In making experiments on animals to ascertain how far the influence of the brain is necessary to the action of the heart, I found that when an animal was pithed by dividing the spinal marrow in the upper part of the neck, respiration was immediately destroyed, but the heart still continued to contract cir­culating dark-coloured blood, and that in some instances from ten to fifteen minutes elapsed before its action had entirely ceased. I further found that when the head was removed, the divided blood vessels being secured by a ligature, the circulation still continued, apparently unaffected by the entire separation of the brain. These experiments confirmed the observations of Mr. Cruikshank and M. Bichat, that the brain is not directly necessary to the action of the heart, and that when the functions of the brain are destroyed, the circu­lation ceases only in consequence of the suspension of respira­tion. This led me to conclude, that, if respiration was produced artificially, the heart would continue to contract for a still longer period of time after the removal of the brain. The truth of this conclusion was ascertained by the following experiment.

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