Papers on dermatology and allied subjects / by E.D. Mapother.

  • Edward Mapother
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: Papers on dermatology and allied subjects / by E.D. Mapother. Source: Wellcome Collection.

    15/144 (page 7)
    hair papilla, sweat or oil gland, and mass of fat, so that the diverse functions of these organs can be independently performed on receipt of the necessary blood. Each papilla has an afferent and an efferent capillary joining above in a loop or loops where much dilatation is found. The arrange- ment is something similar to that of the Malpighian tufts of the kidney and a like effect is produced, namely, a slow- ing- of the blood movement. The functions of the skin in respect to heat and respiration are thereby aided. Here much more heat is given off than produced, and hence the blood becomes cooler in proportion as its stream flows slowly. The vessels abound more at the flexor aspect of the limbs where also the cuticle is thinner—here, therefore, constitutional eruptions, the syphilides and eczema for example, appear most freely. At the extensor surfaces non-diathetic diseases, psoriasis (and perhaps icthyosis may be in that category) will be found. The fibrous tissue and the vessels are arranged in a sloping direction from the spine downwards and forwards in the upper half of the trunk, more horizontally in the lower. In other places, where the cleavage of fibrous tissue is not regular, the vessels assume an arrangement more or less circular. Various eruptions are found to follow these modes of dis- tribution. The lymphatic vessels are no less extensive, and free communication is kept up between them and the great serous cavities by the stomata of the latter, as pointed out by Mascagni so long ago as 1770. The practical application of these points may be con- sidered under two heads, (1) Topical blood-lettings and derivatives, and (2) Clothing. (1) When we draw blood by leeching, cupping, or incision, to relieve hyperaemia of organs or regions, we do not expect that the abstraction from the amount of the entire circulating o fluid will afford the aid which is so often given. Each leech, for instance, removes scarcely so-gth of the total blood, and a dozen of them applied to an adult cannot be supposed to