Explain the term mechanical digestion

Question

Explain the term mechanical digestion? In arthropods, molluscs, earthworms, birds and vertebrates, in common, which organs correspondingly participate in this kind of digestion?

Answer 1

The mechanical digestion is a fragmentation of food aided by the specialized physical structures, like teeth, prior to extracellular digestion. The mechanical fragmentation of food aids digestive enzymatic reactions since it gives a bigger total area for the contact between enzymes and their substrates. In certain molluscs, the mechanical fragmentation is completed by the radula (that is, a teeth-like structure). Various arthropods, such as dragonflies and lobsters, have mouthparts which make mechanical digestion of food. In birds and earthworms, the mechanical digestion is made up by an internal muscular organ. In mandibulate vertebrates, there are mandibles and chewing muscles to triturate food prior to the chemical digestion.