Different types of secreted membrane microparticles. Microparticles or pre-microparticles originally exist in multivesicular bodies. Following cellular activation, multivesicular bodies move close to the cellular membrane. Microparticles that are generated in multivesicular bodies are called exosomes once they are secreted. Secreted vesicles can form inside internal compartments from where they are subsequently secreted by fusion of these compartments with the plasma membrane. This microparticle is called an ectosome. Active calpain cleaves the cytoskeleton, leading to the formation of a membrane bleb and ectosome release. Exosome functionates by delivery system of some cellular substances. Ectosome possesses a procoagulant activity.