Digestion: Where does it go?

Digestion is so EXCITING...okay, maybe not. But it is important. Our bodies use food to help us do things like exercise, work, and play. While some foods begin the digestive process as soon as we bite into it, many foods do not start working to help our bodies immediately. In order for our bodies to be able to use what we eat, the foods must be broken down or digested. Note though, all foods (and medications) are not digested in the same way.

Many of our foods consist of varying combinations of carbohydrates, fats, proteins, vitamins, and minerals, yet most bodies are able to break down those combinations! We have various organs, body parts, and body functions that aid in food digestion. The first body part where food digestion starts is inside our mouth. Specifically, with the use of our teeth and the enzyme amylase found in our saliva, we almost immediately begin to break down our food. Our food then travels down our esophagus to our stomach, through peristalsis movement.

Once food reaches our stomach, it is mixed with gastric juice which starts the digestion of proteins and offers limited absorption, specifically water, salt, and lipid-soluble medications. As the food moves out of our stomach, the next stop is the small intestine where the functions of the pancreas, liver, and gallbladder further aid in the digestive process. The pancreas secretes digestive enzymes that aid in breaking down carbohydrates, proteins, and fats. The liver produces bile to help digest fats while also breaking down carbohydrates and proteins to produce fat molecules. Meanwhile, the gallbladder stores bile made in the liver that aid in fat digestion. There are various functions happening in the small intestine, as a result, a lot of nutrient absorption happens. As the functions of the pancreas, liver, and gallbladder occur, the small intestine receives the secretions from the mentioned organs, absorbing the nutrients through villi, microscopic structures.

Once passed through the small intestine through continued peristalsis, the rest of our food is then stored in the large intestine where water and electrolytes are absorbed. The food which is now feces , stored in the large intestine is held in the large intestine until elimination. Elimination signals the end of our food digestion process.

While the pathway may be consistent, remember, the various food types are absorbed in various ways. Carbohydrate digestion begins in the mouth and completed in the small intestine, being converted into monosaccharides absorbed by the villi. Protein digestion begins in the stomach but still ends in the small intestine, being converted into amino acids. Blood then carries the amino acids for necessary use throughout our body. Fats differ from carbohydrates and proteins as most of their digestion occurs in the small intestine, being converted into chylomicrons. Carried in our blood, the chylomicrons are stored or used immediately as energy supplies.

See, wasn't that exciting!