1. How does food change in consistency and form?
To ease digestion in the stomach, food is broken down mechanically in the mouth through chewing and mixed with saliva to form bolus. Then, when the food reaches the stomach, the bolus is mixed with gastric juices which turns it into chyme, a semi-liquid substance. It then goes to the small intestine, where enzymes and bile further liquifies the chyme for the absorption of nutrients. Finally, it reaches the large intestine, where water is absorbed and solid waste if formed.
2. How could the body absorb the nutrients from the foods we eat?
The nutrients from food are mainly absorbed in the small intestine, where finger-like projections called villi and microvilli increase surface area aid in the process. Proteins are broken down into amino acids, lipids into micelles, and carbohydrates into simple sugars, which are then absorbed into the lymphatic or circulatory systems. All nutrients are carried to the liver for processing and distribution to the rest of the body.