A lecture on the functions of the lymphatic system / [Robert James Graves].

  • Graves, Robert James, 1796-1853
Date:
1828
Catalogue details

Licence: Public Domain Mark

Credit: A lecture on the functions of the lymphatic system / [Robert James Graves]. Source: Wellcome Collection.

    24/24 (page 24)
    returned to the heart by the lymphatics; he does not, however, even hint why it should be so, nor does he seem to have had any notion of its being the venous blood of the white parts of the body. Note.—Dr. Bostock (Elementary System of Physiology, vol. 1. p. 199,) says, that “ in some cases where he had an opportunity of examining the “ foetus immediately after its extraction from the uterus, the different “ colours of the blood in the funis appeared quite obvious/* In the cases observed by Dr. Bostock it is evident that many minutes must have elapsed between the first exposure of the funis to the air and his examination of it. This circumstance alone is sufficient to account for the difference of colour in the blood of the umbilical arteries and vein. Majeydie has shewn (Journal de Physiologie, tom. 1. p. 17,) that the blood contained within the jugular vein in young animals, very soon assumes the arterial colour, when the vein is exposed to the air, and the course of the blood in it retarded by pressure. When the abdomen of a living animal is opened, he says that a similar change of colour may be observed in the blood of the mesenteric veins, in the course of a few seconds. As the coats of the umbilical vein are thinner, and consequently more permeable by the air, than those of the umbilical arteries, a very short time will be sufficient to make an obvious difference in the colour of their contained blood. FINIS.