1. How does the food change in consistency and form?
It goes through a mechanical breakdown process in the mouth through mastication and a chemical process as the food mixes with saliva that contains salivary amylase for enzymatic breakdown. These processes create bolus, a soft and round-shaped structure. As this goes down through the esophagus into the stomach, the bolus is churned with gastric juices until it is chyme, a semifluid mass. Entering the small intestines allows for further chemical digestion as pancreatic enzymes and bile break the chyme down for absorption.
2. How could the body absorb the nutrients from the foods we eat?
Villi, the small, finger-like projections lining the small intestine, facilitate nutrient absorption as chyme arrives in the small intestines. The villi increase the surface area for absorbing nutrients as they consist of projections with lymphatic vessels and capillaries that the nutrients such as glucose, amino acids, fats, vitamins, enter to. The large intestine, then, is a site for undigested material, water absorption, and elimination of waste.