- How does the food change in consistency and form?
- The food travels through several organs that manipulate its consistency and form. It enters the mouth where it is broken down mechanically and chemically through chewing and enzymatic breakdown—producing bolus. From there, it moves down the esophagus and into the stomach to make chyme, a result of continuous churning and hydrolysis. The acid and enzymes of the stomach break down the food until it has the consistency of liquid or paste. As the food passes through the intestines, the nutrients are absorbed. In the large intestine, water is extracted, and the remaining material is transformed into stool.
- How could the body absorb nutrients from the foods we eat?
- As the food moves through the gastrointestinal tract, the digestive system breaks down into its simplest forms like glucose, amino acids, or fats which are primarily absorbed by the small intestine. This is facilitated by the villi—tiny finger-like projections that line the intestinal walls and increase the surface area for nutrient absorption. Each projection is made up of a network of capillaries and lymphatic vessels that enable diffusion of water-soluble nutrients. Lastly, after all the nutrients have been absorbed, the waste is moved into the large intestine where water is removed, making stool.