Our present knowledge regarding muscular atrophies and hypertrophies / by Landon Carter Gray.

  • Gray, Landon Carter, 1850-1900.
Date:
[1888]
Catalogue details

Licence: Public Domain Mark

Credit: Our present knowledge regarding muscular atrophies and hypertrophies / by Landon Carter Gray. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    portion of the third ventricle. It is always, without a known fact to the contrary, motor in its function, and gives origin only to the motor nerves. At the present day our knowledge is very exact concerning the levels in which the different motor nerves thus have their origin, commencing above with the third pair, or motor oculi, and passing down to the nerves of the lower extremities. Fig. I will show the intracranial portion of this gray matter, and should be care- fully studied. It represents a longitudinal section through the center of the intracranial mass, showing the ventricular cavities and their relations. The nerve cells within this an- terior column of gray matter are known as the ganglion cells. They are of considerable size and endowed with a distinct nucleus aud nucleolus and with a number of protoplasmic prolongations running off from the body of the cell, known as processes. These processes art' of two kinds. One branches and rebranches as it passes away from the cellular body, growing smaller as it goes, and is called the M protoplasmic process.” The other does not branch a» it passes away from the cell, but grows slightly larger, and ha* been seen by a great number of competent observer* to take on a covering of myelin and pass to the periphery; hence, it is extremely probable that it represents the axis-cylinder of a peripheral nerve, and it is called the “ axis-cylinder pro- cess.” The termination in the muscle* of the nerve-fibers thus originating has been carefully investigated by many of the best-known histologists of the day ; most recently by Gessler in the green Italian lizard and the guinea-pig- Gessler states that the motor end-plate is essentially the same in the Mammalia and reptile*. This motor end-plate consists of a fine nerve-plexus between or under which—for authors differ on this very immaterial point—lies a finely granulated ma*s, containing two varieties of nuclei—the one kind, the smaller, being granulated and of irregular shape;