Gastrointestinal Physiology, Part 1

The food that we ingest travels from the mouth to the anus. Along this route, the composi­tion of the luminal content changes significantly, since some of the constituents are removed while others are added and eventually food is transformed into feces. This article begins with a detailed outline of gastrointestinal motility. The latter supports the mostly unidirectional longitudinal movement of the luminal content while also allowing – in a controlled manner – for the content to be retained in the cavities of the gastrointestinal tract. In the following two chapters, the physiology of the stomach, salivary glands and pancreas is covered. These organs crucially alter the mechanical and chemical composition of the bolus to enable the assimi­lation of nutrients, as well as the absorption of vitamins, minerals, electrolytes and water that are discussed in the following article, i.e. the Gastrointestinal phisyology, part 2. The clini­cal boxes are provided to help the reader along his passage through the text, strengthen the contextual connection between the two parts and exemplify the use of basic knowledge in clinical practice.