Topic overview

Start with the big picture

Emboli may be solid, liquid, or gaseous; most arise from dislodged thrombi, while other sources include fat, air or nitrogen, amniotic fluid, atheromatous debris, tumor fragments, and foreign bodies. The lesson distinguishes pulmonary from systemic embolism and introduces paradoxical, fat, air, and amniotic fluid embolism. Infarction is ischemic necrosis caused by arterial occlusion or impaired venous drainage. Infarcts may be red or white, with their appearance influenced by tissue structure and blood supply. Venous infarcts are typically red; brain infarcts undergo liquefactive necrosis, whereas most other infarcts show coagulative necrosis. These patterns provide a foundation for understanding how vascular obstruction affects different organs.