Embolism

(em'-bo-lizm). The obstruction of an artery or capillary, usually by a blood-clot or embolus, brought from another point by the blood-current. These emboli may be fragments of vegetation from the valves of the heart, clots from a thrombosis or aneurysm, or fragments of atheromatous ti ue. Around the seat of an embolus thrombosis occurs with the production of an infarct, q. v. E., Air, by a bubble of air. E., Capillary, obstruction of capillaries by micrococci. This occurs in pyemia. E., Fat, the entrance into the circulation of fluid fat after extensive injuries. Death often follows. The symptoms are restle ne , anxiety, slight dyspnea, accelerated breathing, quickening of the pulse; cyanosis, delirium, and insomnia, followed by coma, are graver symptoms. The temperature may remain subnormal or it may rise. E., Infective, the emboli are metastatic. This occurs in pyemia and ulcerative endocarditis. E., Multiple, numerous small emboli. E., Paradoxical, embolism of an artery by a venous thrombus, as may occur in a patulous foramen ovale. E., Pyemic. See Infective . E., Retinal, occurring in the arteria central is retinae, followed by sudden lo of vision. E., Venous, occurring in veins, especially of the lungs and liver. Scheme of a Longitudinal Section through an Embryo after the Formation of the Head and Tail-Folds. Ao. Omphalo-mesenteric arteries. Vo Omphalo-mesenteric veins, a. Position of the allantois. A. Amniotic fold. Scheme of a Longitudinal Section through a Human Ovum. Z. Zona pellucid a. S. Serous cavity, r. Union of the amniotic folds A. Cavity of the amnion, a. Allantois. X. Umbilical vesicle, m. Mesoblast. h. Heart. U. Primitive intestine.