Vesicles

Vesicles is a term used in cellular biology to refer to small structures, similar to blood vessels, that are found both inside and outside the cell but consist of fluid enclosed with a bilayer of lipid (fatty cells) rather than a formal vascular structure. Unlike blood vessels, these particular structures form naturally during the processes of secretion (exocytosis), uptake (endocytosis) and transportation of materials within the cytoplasm.