1. How does the food change in consistency and form?
The consistency and for of food changes as it passes through the various organs of the digestive tract; and this immediately starts as it enters the mouth. The mouth facilitates chewing that breaks up the food into smaller pieces, at the same time, salivary enzymes break down these small pieces and turn them into bolus. This bolus passes through the esophagus and enters the stomach where churning occurs and enzymes break it down to form a more fluid substance called chyme. The chyme passes through our small intestines where nutrients are absorbed then moved into the large intestine, by the time it is in the large intestine, the chyme has undergone water absorption and is now solid/semi-solid and is now called feces.
2. How could the body absorb the nutrients from the foods we eat?
90% of water and nutrient absorption occurs in the small intestine, after enzymes from the digestive system have successfully digested the carbohydrates, lipids, nucleic acids and proteins, the small intestine’s fold, villi and microvilli absorb these substances through processes like diffusion, facilitated diffusion, osmosis and active transport. Remaining water, electrolytes and ions not absorbed by the small intestines are then absorbed by the large intestines.