We all know that it is important to eat food, especially healthy food, to supply our body with all its nutritional requirements. However, not many of us know how the body digests and uses the food we eat. Let’s take a look at this process in more detail.
How is food digested?
Digestion starts in the mouth where the food is chewed by the teeth to break it down for easier digestion. The mouth also produces saliva, which contains a digestive enzyme called amylase to begin breaking down the carbohydrates and sugars. Once the food is swallowed it travels into the stomach via the esophagus.
The stomach churns the food to break it down further and mixes it with other digestive enzymes and hydrochloric acid to break it down into simple structures for absorption (small molecules such as, glucose or alcohol, are directly absorbed into the blood stream from the stomach). Another substance called gastric intrinsic factor, essential for the absorption of Vitamin b12 is released by the parietal cells of the stomach.
After this process is complete the food moves into the small intestine where the changing pH level activates more digestive enzymes to split the complex structures into simple structures so that they can be directly absorbed into the lymphatic or circulatory systems. The small intestine also releases bile to help digest the fats, pancreatic juices and more digestive enzymes to process complex sugars. Absorption occurs in the small intestine as the nutrients are now small enough to pass through the intestine wall. This wall contains villi, which are small finger-like structures that increase the surface area of the intestine for improved absorption. The nutrients are carried to the liver for filtering, nutrient processing and toxin removal.
The final stage of the process occurs when food enters the large intestine. Food in this region is fermented by helpful bacteria, which can recover some of the remaining useful substances for absorption. Foods that cannot be digested mix with other waste products to become feces, which is eliminated from the body.