The students constructed a model of the digestive system using playdough, clothes pins, cardboard, and other materials. They made the esophagus, stomach, liver, large intestine, and small intestine. The digestive system breaks down food through processes like chewing, stomach acid, and enzymes in the small intestine to extract nutrients, which are then absorbed in the bloodstream. Waste products then move to the large intestine, rectum, and are excreted.