Selections in Pathology and Surgery Author:John Davies Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: 2. That the proportion is governed by a vital property residing in the coats of the vessels, and bearing a relation to the blood within them. 3. That any redu... more »ction in the amount of the vital power of the vessels will allow their calibre to be enlarged by the force of their elasticity; 4. That the immediate consequence of a preternatural enlargement of the vessels is an increased influx of blood into them; 5. That the visible phenomena of inflammation result from a number of the capillary branches of the arteries having lost a part, or the whole, of their contractile power, thereby having become enlarged in their calibre, so as to admit, and retain, an undue proportion of blood. 6. That, while the capillaries are in the state last mentioned, the velocity of the blood within them undergoes a decrease, although the quantity of fluid existing in them has acquired an increase; which increase imparts to the seat of disease the character of redness. 7. That the strength of the pulsation of an artery—in other words, of the " pulse "—bears some ratio to the size of the vessel at the point where it is felt. Thus, if a branch whose diameter in one part is equal to 2, expands a short distance further on into a diameter equal to 4, the "pulse" felt at the latter part of the branch will be much stronger than that felt at the former, where the tube is smaller, although the latter is nearer the heart, which is the source of the pulsation. 8. That the throbbing felt in an inflamed part depends upon an increase of size which the capillaries have acquired in consequence of a reduction, or loss, of their contractile power; thereby presenting a larger internal surface to the force of the heart through the medium of the column of blood; and, 9. That, the preternatural expansion may...« less