Licence: Public Domain Mark
Credit: An introduction to pathology and morbid anatomy / by T. Henry Green. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![mucli the less frequent form of calcification. It occurs in some forms of softening of bone, especially in extensive caries and osteomalacia. In these diseases the lime salts are removed from the bone, returned into the blood, and some of them deposited in other tissues. In such cases the calcification is usuallj- more or less general—many organs being simultaneously involved. In osteomalacia, it is not uncommon to find the kidneys, the lungs, the stomach, the intestines, and even the dura mater and Hver, infiltrated to a greater or less extent with Hme salts. The deposition commences in the tissue immediately surrounding the blood-vessels from which the calcareous matters are derived;—thus, in the lungs, the seat of the change is the interlobular tissue; in the stomach, the stroma between the glands ; and in the kidney, the tubuli nriniferi and the interttibular tissue. Precisely analogous to this form of calcification is the deposition of the excess of urate of soda which takes place in gout. In the great majority of cases, however, calcification is a local change, dejpending not upon any alteration in the composition of the blood, but upon changes in the tissues themselves, owing to which some of the saline matters which are normally held in solution in the blood are de- posited in them. The alteration in the tissues consists in some impairment of their ntitrition, associated with a diminution in their amount of blood, and a retardation of its circulation. All those conditions which tend to pro- duce atrophic and retrogressive changes in a part, and at the same time to interfere with the circulation in it, are liable to be followed by its calcification. Inflammation, diminished nutritive supply, and general impau-ment of vitahty, may all of them give rise to this ]3rocess. This is seen in the calcification of atheromatous arteries, of caseous masses in the lungs and lymphatic glands, of many new formations, and of the blood-vessels and car- tilages in old people. In its morbid antecedents calcifi- cation thus somewhat resembles fatty degeneration, and](https://iiif.wellcomecollection.org/image/b21915830_0114.jp2/full/800%2C/0/default.jpg)
