A tube is a hollow, cylindrical form (plate 5C&F). It can function as a pipe or as a structural form. However as mentioned above tube and pipe both may appear same but they have specific characteristics, which may be applied for specific work. Tubes are quite common in nature. Stem of a plant (plate 5G) has tubular structure to pass fluid. Our body has miles of tubes (plate 5D&E), to carry blood, fluids, and other things. Veins, hoses (plate 5F) to and other similar things have the properties to carry liquid, fluid, or gas through an enclosed sheet of material.
