Читать книгу The Body at Work: A Treatise on the Principles of Physiology онлайн

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It is almost hopeless to attempt to disentangle the various factors which disturb the balance between blood and lymph—excessive outflow from blood, deficient inflow from lymph, stretching of the endothelium of the capillary tubes, imperfect nutrition and consequent imperfect apposition of the endothelial scales, increased permeability of the scales. The exudation which accompanies inflammation would seem to be due to the diminished vitality of the endothelium rather than to a mechanical factor, such as increased blood-pressure in the capillaries, and their consequent distention. Ascites is, apparently, a purely mechanical result of the resistance offered to the passage of blood through the liver; but pleurisy, the accumulation of lymph in the space between the lungs and the chest-wall, cannot be explained in the same way. There is no undue pressure on the vessels in which the blood circulates through the inflamed pleura (the investing membrane of the lungs and lining membrane of the chest), yet the walls of the capillaries fail to maintain a proper balance between blood and lymph.