The Digestive Tract: A Complex System

  • Alan MackieEmail author


The digestion is a complex process that converts a range of different types of food into molecular scale nutrients that can be absorbed in a controlled manner. This is achieved while simultaneously maintaining a barrier to infection. The gastrointestinal tract has evolved to extract the maximum amount of nutrients from our diet and this is achieved in a number of different stages that match patterns of eating. The oral phase breaks food into small particles and provides the first biochemical assessment of how palatable the food is. From the mouth, food passes into the stomach for storage and controlled release into the small intestine, where most of the digestion and absorption takes place. Finally food that has not been digested passes into the large intestine where it is partially fermented into useable nutrients by the gut microbial community. All these steps are tightly controlled by numerous feedback mechanisms controlled by the neuroendocrine system that also links to appetite response.


Food digestion Oral Gastric Intestinal Mucosa Feedback 


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© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.School of Food Science and Nutrition, University of LeedsLeedsUK

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