A manual of surgery : for students and practitioners / by William Rose and Albert Carless.

  • Rose, William, 1847-1910.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: A manual of surgery : for students and practitioners / by William Rose and Albert Carless. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    enabled to escape into the perivascular tissues, and there produce the clinical effects so commonly seen. The actual phenomena of inflammation may perhaps best be studied in the web of a frog’s foot. If this is spread out and examined under the microscope, the following evidences of physio- logical activity may be seen : {a) the flow of blood through the vessels, as indicated by the movement of the corpuscles, the red ones, each separate from the other, flowing in the central or axial current, the leucocytes occasionally seen amongst the red, or here and there one may be noticed rolling lazily along in the inert corpuscle-free peripheral portion of the tube; {h) the constant changes in calibre of the arterioles independent of the heart’s rhythmical action, and influencing in a marked degree the flow through the capillaries; and (c) the changes which occur in the pigment-cells, which represent the connective tissues of the part. These are mainly due to the influence of light, the cells contract- ing or expanding as the light is increased or diminished. If now a crystal of common salt, or some such irritant, is applied to the web, the early vascular phenomena contributing to inflammation may be readily observed. I.—The Vascular Changes in Acute Inflammation. A momentary contraction may perhaps be noticed in the arterioles of the part, but this is only apparent in inflammatioiis produced artificially, and is of no known significance. It is followed by a condition of Hypersemia of the inflamed area, as manifested by a rapid and lasting dilatation of the vessels, accom- panied by an increase in the rapidity of the blood-flow {accelera- tion). This is a peculiarly vital phenomenon, and opposed to the hydrostatic law that when fluid is flowing through a tube or channel at a fixed pressure, if the lumen is suddenly widened, the rate of the blood-flow is diminished. It is probably brought about by some change in the local vasomotor mechanism present in the smaller arterioles. This increased rapidity of the flow lasts for a while, and then the current gradually becomes slower and slower [retardation], as if an ever-growing obstruction existed to_ the passage of the blood ; then a period of oscillation will be noticed, the blood-current swaying forwards and backwards, and finally a condition of stasis or still-stand is arrived at, which may or may not end in actual thrombosis or intravascular coagulation. this period changes have occurred in the behaviour ot the blood contained in the vessel, due in all probability to certain inyisi e changes in the vessel walls and not to any alteration in the blood Thus, almost as soon as dilatation occurs, the leucocytes collect along the walls in the peri-axial inert layer, seeming, as it were, to fall out of rank; this process first commences in the veins, but can be observed in all the vessels. The red corpuscles also.