Mechanical digestion is the fragmentation of food aided by specialized physical structures, such as teeth, previous to extracellullar digestion. The mechanical fragmentation of food helps digestive enzymatic reactions because it provides a larger total area for the contact between enzymes and their substrates.

In some molluscs, the mechanical fragmentation is done by the radula (a teeth-like structure). Some arthropods, like lobsters and dragonflies, have mouthparts that make mechanical digestion of food. In earthworms and birds, the mechanical digestion is made by an internal muscular organ. In mandibulate vertebrates there are mandibles and chewing muscles to triturate food previous to the chemical digestion.   _{Your Comment}