When the food in the mouth, then mash to blend into the local. The muscles in the stomach will expand to contain food and mechanical. By enzymes in complex chemical sub-regurgitation
When cooked food in the mouth and then swallowed into the belly muscles in the stomach expands to fill food and mechanical. In the enzymatic digestion because food chemistry.
When the mixed food in the mouth and swallow into the stomach muscles in the stomach to expand to packaging of food and food, mechanical properties The enzymes in the stomach digest of chemistry.