First off, our teeth grind food into small pieces and the tongue helps us to swallow this mushy pulp. This is then carried to our stomach by the oesophagus. The stomach the breaks down the food by pounding it through muscle contraction before passing it to the small intestine.
Intestines further break food particles into smaller molecules that can pass through the walls of intestine into the bloodstream. The food that cannot be digested further is passed to the large intestine and then expelled from the body.