A text-book of human physiology : designed for the use of practitioners and students of medicine / by Austin Flint.

  • Flint, Austin, 1836-1915.
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of human physiology : designed for the use of practitioners and students of medicine / by Austin Flint. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    35/1010 (page 13)
    which show an increase in the number of corpuscles in the blood coming from the spleen and a diminution in the blood of the hepatic veins, are not sufficiently definite to serve as a' demonstration that the spleen is a blood-forming organ; and the same remark may be applied to observations upon the formation of blood-corpuscles by the marrow of the bones. ^ , In the present state of our knowledge, the foUowmg seem to be the most rational views with regard to the development and nutrition of the blood-corpuscles: 1. At the time of their first appearance in the ovum, they are formed by no special organs, for no special organs then exist; but they appear by genesis in the sanguineous blastema. 2. When fully formed, they are regularly-organized anatomical elements, subject to the same laws of gradual molecular waste and repair as any of the anatomical elements of the tissues. 3. They are generated de novo in the adult, when diminished in quantity by htemor- j rhage or otherwise; and, under these circumstances, they are probably formed in thej liquor sanguinis, by the same process by which they take their origin in the ovum. Function of tJie Blood-Corpuscles.—Mthongh the albuminoid constituents of the plasma of the blood are essential to nutrition, the red corpuscles are the parts most immediately necessary to life. We have already seen, in treating of transfusion, that life may be re- stored to an animal in which the functions have been suspended from haemorrhage, by the introduction of fresh blood; and, while it is not necessary that this blood should contain the elements of fibrin, it has been shown by the experiments of Prevost and Dumas and others, that the introduction of serum, without the corpuscles, has no restorative effect. When all the arteries leading to a part are tied, the tissues lose their properties of con- tractility, sensibility, etc., which may be restored, however, by supplying it again with the vivifying fluid. We shall see, when we come to treat of the function of respiration, that one great distinction between the corpuscular and fluid elements of the blood is the gi-eat capacity which the former have for absorbing gases. Direct observations have shown that blood will absorb from ten to thirteen times as much oxygen as an equal bulk of water; and this is dependent almost entirely on the presence of the red corpuscles. As all the tissues are constantly absorbing oxygen and giving off carbonic acid, a very im- portant function of the corpuscles is to carry oxygen to all parts of the body. In the present state of our knowledge, this is the only well-defined function which can be attributed to the red corpuscles, and it undoubtedly is the principal one. They have an affinity, though not so great, for carbonic acid, which, after the blood has circulated in the capillaries of the system, takes the place ot the oxygen. In some experiments per- formed a few years ago on the efifects of hemorrhage and the seat of the iesoin de re- spirer, we demonstrated that one of the results of removal of blood from the system was a condition of asphyxia, dependent upon the absence of these respiratory elements. Leucocytes, or White Corpuscles of the Blood.—In addition to the red corpuscles of the blood, this fluid always contains a number of colorless bodies, globular in form, in the substance of which are embedded a greater or less number of minute granules. These have been called by Robin, leucocytes. This name seems more appropriate than that ot white or colorless blood-corpuscles, inasmuch as they are not peculiar to the blood, but are found in the lymph, chyle, pus, and various other fluids, in which they were formerly known by different names. All who have been in the habit of examining the animal fluids microscopically have noticed the great similarity between the corpuscular elements found in the above-mentioned situations; and, as microscopes have been improved and investigations have become more exact, the varieties of corpuscles have been narrowed down. It is now pretty generally ackuowlodgcd that the corpuscles found in mucus and pus are identical; also, that there is no difference between the white corpuscles found in