KnowraDigestionDigestionDigestion is the mechanical and chemical breakdown of food into molecules that can be absorbed and used by the body.BriefConnectMastication: The chewing of food, which breaks it into smaller pieces and mixes it with saliva. It begins mechanical digestion and prepares food for swallowing.Gastrointestinal tract: The continuous muscular passage from mouth to anus through which food travels. It is the route along which digestion takes place.Malabsorption: Impaired absorption of nutrients from the digestive tract. It shows how digestion can proceed while nutrient uptake still fails.Absorption: The movement of substances from the digestive tract into blood or lymph. Digestion breaks food down; absorption moves the resulting nutrients into the body.Peristalsis: Waves of coordinated smooth-muscle contraction that propel contents through the digestive tract. These contractions move food between digestive organs.Saliva: Fluid in the mouth that lubricates food and contains substances that begin digestion. It moistens food and starts starch breakdown during chewing.Lactose intolerance: Digestive symptoms caused by insufficient lactase activity and poor lactose absorption. It is a common example of impaired digestion of a specific nutrient.Metabolism: The chemical reactions that build, break down, and transform substances within an organism. Metabolism uses absorbed nutrients, whereas digestion acts on food in the gut.Gastric acid: Hydrochloric acid secreted by the stomach that creates a strongly acidic environment. It denatures proteins and supports the action of stomach enzymes.Stomach: A muscular organ that stores food and mixes it with acid and digestive enzymes. It churns food and begins substantial protein digestion.Show all 23Linked from 22 pagesDigestive System and Oral Physiological PhenomenaBroader topic: It is the central process represented by this physiological category.HydrolysisRelated: Digestive enzymes hydrolyze food polymers into absorbable products.GizzardNarrower topic: The gizzard performs the mechanical stage before chemical digestion continues.Intestinal absorptionCompared with: Digestion produces absorbable molecules; absorption then transfers them out of the lumen.OmnivoreRelated: Omnivores rely on digestive processes that can handle nutrients from both plants and animals.FlatulenceNarrower topic: Incomplete digestion of some carbohydrates leaves material for intestinal microbes to ferment.NutrientRelated: Digestion releases nutrients from food matrices and converts some into absorbable molecules.MacronutrientRelated: Digestive processes make many macronutrients available for absorption.Show all 22