N3 Anatomy and Physiology AY 2024-2025

How does the food change in consistency and form?

1. Mouth:  Food is ground in the mouth through mastication or chewing. It also mixes with the saliva containing salivary amylase, creating a bolus easier to swallow.
2. Stomach: As the bolus is mixed with gastric juices breaking down proteins and lipids, the mixing action also causes the bolus to disintegrate creating a substance called chyme.
3. Small Intestine: Segmentation of the intestine causes the chyme to mix with pancreatic juices which further emulsifiers proteins, carbohydrates, and lipids.
4. Large Intestine: As water is continuously absorbed in the stomach, chyme becomes a solid substance called feces.

How could the body absorb the nutrients from the foods we eat?

1. Digestion:  It breaks down molecules, with the help of digestive enzymes & bile, into simpler substances that can easily pass through the epithelium.
2. Small Intestine:  This is the location of the majority of nutrient absorption either through active transport, facilitated diffusion, or simple diffusion. Active transport can also occur through secondary transport mechanisms in which one ion follows its concentration gradient while the other goes against it.