Volume 2

Human physiology / by Robley Dunglison.

  • Dunglison, Robley, 1798-1869.
Date:
1856
Catalogue details

Licence: Public Domain Mark

Credit: Human physiology / by Robley Dunglison. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    important to the proper action of certain organs, is exhibited in the pulsation of the different arteries. It has been seen, that a succussion is in this way given to the brain, which appears to be necessary to it; for if this source of stimulation be in any manner withdrawn fainting is induced. Perhaps, however, the strongest case that can be offered of modification of function by mechanical causes, is that of the gravid uterus, which, by its pressure, gives rise to numerous symptoms in other organs, that are often the source of annoyance during gestation. 2. FUNCTIONAL CORRELATIONS. The functional correlations or synergies are of much more moment to the physiologist and pathologist. Many of these have also been described in the preceding histor}^: a brief notice of them will be all that is now requisite. For the maintenance of the healthy function we know that certain conditions are necessary, and that if these be materially modified, in the whole or in any part of the body, disease and death may be the result, even although the derangement may, in the first instance, concern only an apparently unimportant part of the frame,—the affection, by correlation, spreading gradually to more and more essential organs and functions, until the disorder is ultimately too great to allow of a continuance of the vital movements. In this respect, man differs from an ordinary piece of mechanism, in which the various parts are so adapted to each other as to produce a certain result. If one of these parts be destroyed, the whole machine may have its motion arrested ; but the effect is owing to the destruction of one part only, the others remaining sound ; whilst death, or the stoppage of the living machine, does not necessarily follow the destruction of any except a few essential organs, and is generally owing to the derange- ment of many. AVe shall find, indeed, that except in cases of sudden death, it is extremely difficult to say which of the three truly vital organs has first ceased to act; and that in all such cases death begins D / O in one or other of the organs essential to vitality, and soon extends to the rest. The essentially vital organs are those of respiration, circulation, and innervation; but the great use of respiration is to change the blood from venous to arterial; in other words, to induce a conversion in it by its passage through the lungs, without which it would be inadequate for the maintenance of life in any organ; and the object of the circu- lation is, to distribute it to the various parts of the frame as the grand vivifying and reparatory material. If, also, the organs of innervation be destroyed, the nervous influence is no longer conveyed to the different parts of the frame ; and as the presence of this influence is indispens- able, the functions may cease from this cause ; so that we may regard as essential elements to the existence of the frame and of every part of it a proper supply of arterial blood and nervous influence. In the production and distribution, however, of these agencies, a number of functions is concerned, giving rise to the correlation, which is the object of the present inquiry. If, in any manner, the blood does not meet with due aeration, as in ordinary cases of suffocation, death supervenes in the order elsewhere described ; and if a slight degree of aeration is accom- plished, but still not enough for the necessities of the system, instead