Selected monographs on dermatology / Unna, Nielsen, Duhring, Bronson, Blanc, Berger, Prince-Morrow.

  • New Sydenham Society.
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs on dermatology / Unna, Nielsen, Duhring, Bronson, Blanc, Berger, Prince-Morrow. 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.

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    general contraction of the arteries drives the blood into the veins ; when the rigor mortis ceases the blood from these regurgitates into the capillary areas, which become enlarged and of a bluish-black colour. The author then describes the congestion of the legs and feet which occurs in people who stand a great deal; and he traces the steps by which the veins, from being merely over-filled in the earlier stages, become varicose later on. Y. CEdema.1 We must distinguish between two kinds of oedema, inflammatory and mechanical. The pathology of mechanical (edema of the skin has not been sufficiently studied, and is generally misunderstood. Experimental pathology has taught us that the closure of all the lymphatic channels of a limb does not cause oedema in it, while an obstruction in the veins never fails to give rise to oedema. As a natural conclusion from these two facts, the author states that the lymphatics of the skin are only an occasional channel for the return of lymph. The lymphatics of the skin carry back to the blood only that small fraction of lymph which does not return by the venous capillaries into the veins. The skin is able, by means of its permanent elasticity, to drive along the lymphatics the small quantities of lymph which they normally contain. A more extensive employ- ment of the lymphatic channels is abnormal, and leads to a softening of the tissues,—to, in fact, oedema. We do not, of course, deny that obstructions in the lymphatics themselves, especially when they are numerous and high up, may increase oedema. The discovery of such obstructions, however, even the complete obliteration of the thoracic duct, does not by itself explain the occurrence of oedema of the skin. In every case of oedema we have to determine what has prevented the lymph of the skin from returning by its proper channels, the veins.