scholarly journals On the Occurrence of Amblyopia, long after the Injury, in Cases of Concussion of the Spinal Marrow

BMJ ◽  
1869 ◽  
Vol 2 (447) ◽  
pp. 84-85
Author(s):  
T. W. Jones
Keyword(s):  
Spinal Marrow

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.

scholarly journals III. Observations on the changes the ovum of the frog undergoes during the formation of the tadpole

1825 ◽  
Vol 115 ◽  
pp. 81-86
Keyword(s):  
General Principle ◽  
Spinal Marrow ◽  
Similar Series ◽  
The Brain

In the year 1822, I laid before the Society a series of observations on the progress of the formation of the chick in the egg of the pullet, illustrated by drawings from the pencil of Mr. Bauer, showing that in the ova of hot-blooded animals the first parts formed are the brain and spinal marrow. I have now brought forward a similar series on the progress of organization in the ova of cold-blooded animals, illustrated in the same manner by microscopical drawings made by the same hand. By comparing together the first rudiments of organization in the ova of these very distinct classes of animals, I shall be able to prove that, in both, the same general principle is employed in the formation of the embryo.

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 On the mode of formation of the canal for containing the spinal marrow, and on the form of the fins (if they deserve that name) of the Proteo-saurus

1833 ◽  
Vol 2 ◽  
pp. 128-128
Keyword(s):  
The Body ◽  
Spinal Marrow ◽  
Spinal Process ◽  
Cartilaginous Fishes ◽  
Lateral Branches

The structure of the vertebrae of the Proteo-saurus is intermediate between that of the lizard tribe and cartilaginous fishes, and they have so close a resemblance to the vertebrae of the shark, as often to have been mistaken for them. They are composed of hope, and have a body and canal for the spinal marrow, and a process for the attachment of muscles; but the body is made up of one piece, while the spinal process, and two lateral branches which belong to it, are made up of another; between these there is no union but a species of joint peculiar to themselves; the hole in the middle thus formed appears unusually small. In the specimen from which the above description is taken, there is also a fore foot, paddle, or fin,—for it is difficult to say which it should be called,—and which, though not quite perfect, is more so than in any other extant specimen. It presents nothing like the thumb or claw for laying hold, which distinguishes the animals that occasionally inhabit the sea, and come ashore to lay eggs or deposit young. If it be called a fin, it is to be understood as made up of bony materials, the joints of which are extremely numerous, so that it may possibly perform the same office.

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