Deconstructing Digestion: A Step-By-Step Process

Your digestive system at work!

The digestive system is a vital part of the human body; it's the mechanism that allows us to absorb the macronutrients and micronutrients contained in food. The average adult takes between 24 and 72 hours to fully digest food.

How Does It Work?

The Mayo Clinic breaks down the digestion process—describing it from the first smell of delicious food until excretion.

  1. Digestion starts as soon as we smell food. Our salivary glands make saliva in our mouths, while our stomachs create the acid that will break down the food once it reaches our stomachs.
  2. The tongue and teeth are the first stop in the digestive system. Chewing not only makes food easier to swallow, but begins breaking it down so the nutrients can be absorbed when the food reaches the intestines.
  3. The esophagus connects the mouth to the stomach. When we swallow food, the muscles in the esophagus contract and relax in a pattern that guides the food to the stomach.
  4. When the food enters the stomach, the acids and enzymes produced by the stomach lining break the food down further. The food is liquefied and moved in very small increments into the small intestine or duodenum.
  5. The small intestine contains enzymes produced by the intestine itself and the pancreas, liver and gallbladder. When the liquefied food, known as chyme, moves into the small intestine, it mixes with these enzymes.
  6. After the chyme has been mixed with the enzymes, it is absorbed by the intestine as it moves through the small intestine. Water and waste are leftover from the absorption process.
  7. After the nutrients are absorbed, the waste and water move through the large intestine, or colon, where most of the water is absorbed. The colon forms stool, and expells it through the anus.