THE CAUSES AND MECHANISM OF THROMBOSIS

Abstract

Thrombi are of three kinds, those formed by (1) agglutination of blood cells, (2) coagulation of blood plasma, or (3) a combination. Cell agglutination is promoted by softening of the ectoplasm, reduction of surface electric charge, or deposition of proteins upon the cell surfaces, and all of these changes may be caused by slight changes in the chemical composition of the medium surrounding the cells. Coagulation-promoting factors, in connection with thrombosis, are: increase of the globulin-fibrinogen fraction of the blood relative to the albumin fraction, extraction of blood coagulins from disintegrated agglutinated thrombocytes or from fibrin, extraction of tissue coagulins from disintegrated red cells, vessel walls, or neighboring muscle tissue, parenteral administration of colloids, microorganisms, or other foreign bodies. In connection with both agglutination and coagulation, such mechanical factors as the rate of flow of blood are important. The endothelium plays a role and the inflammatory processes may be significant.