Definition: Extracellular membrane vesicles generated by the shedding of CELL MEMBRANES blebs. Microparticles originating from PLATELETS; ENDOTHELIAL CELLS; and other cell types circulate in the peripheral blood and through the MICROVASCULATURE where larger cells cannot, functioning as active effectors in a variety of vascular processes such as INFLAMMATION; HEMOSTASIS; angiogenesis; and vascular reactivity. Increased levels are found following stimulation of bleb formation under normal or pathological conditions.
