bleb cellular_component plasma membrane bleb GO:0032059 Wikipedia:Bleb_(cell_biology) A cell extension caused by localized decoupling of the cytoskeleton from the plasma membrane and characterized by rapid formation, rounded shape, and scarcity of organelles within the protrusion. Blebs are formed during apoptosis and other cellular processes, including cell locomotion, cell division, and as a result of physical or chemical stresses. plasma membrane bounded cell projection