# Digestive System --- The **digestive system** is an [[organ system]] that breaks down and absorbs [[nutrients]] from the food that we eat. It is comprised of the [[gastrointestinal tract]] which is essentially one long tube that the food passes through, and the accessory organs that support the GI tract organs by making substances that aid in [[digestion]]. ![[digestive system.png]] ## Anatomy The [[gastrointestinal tract]] or **GI tract** are the digestive organs that actually has food pass through it. The "donut hole", so to speak. It is largely divided up into: - the upper GI tract - [[mouth]] - [[esophagus]] - and the lower GI tract - [[stomach]] - [[intestines]] - [[small intestine]] - [[large intestine]] The accessory organs aid [[digestion]] by making and secreting the enzymes and other substances that aid the process. In rough order: - the [[salivary glands]] - the [[liver]] - the [[liver|gallbladder]] - the [[pancreas]] ## Physiology The digestive system has three main functions, **digestion**, **absorption** and **elimination** [[Digestion]] is the process of breaking down the food we eat both mechanically (by breaking it into smaller and smaller physical pieces) and chemically (by breaking the relatively large [[macromolecules]] into their monomers ([[amino acids]], [[monosaccharide|simple sugars]] and [[glycerol]] and [[fatty acids]]) so that we can use them for our own bodies. This largely happens in the upper GI, stomach, and the start of the intestines. [[nutrient absorption]] is the process of taking those nutrients inside the body so that we can use them for ourselves. This largely happens in the small intestine. [[Bowel elimination]] is the removal of solid waste from the body. ([[Urine]] is its own system, which doesn't come from the intestines but from the blood.) ## Problems with the GI System A lot can mess with the GI system, because it's so large and has so many different aspects to it. Common problems: - pain - [[dysphagia]] - dyspepsia, or heartburn - pyrosis, or also heartbutn - intestinal gas, belching or farting - nausea and vomiting - [[diarrhea]] - [[constipation]] ___