Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Organs of the Digestive System The digestive system is generally divided into two main categories: organs of the alimentary canal (aliment = “nourish”) and accessory digestive organs. The alimentary canal, also called the gastrointestinal (GI) tract or gut, is a continuous muscular tube that runs from the mouth to the anus. The internal space of this tube is called the lumen. The GI tract is involved with the digestion of food –its breakdown into smaller fragments – and the absorption of digested food fragments from the lument through the alimentary canal wall and into the bloodstream. The accessory digestive organs contribute to secretions to the GI tract, but the food doesn't pass through these organs. Digestive System organs. This work by Cenveo is licensed under a Creative Commons Attribution 3.0 United States . Different digestive system organs are responsible for different digestive processes and functions. These functions include: extracting nutrients from food and removing waste. The processes by which these occur are called ingestion, motility of food through the GI tract lumen, mehcanical and chemical digestionof the food, absorption and breakdown of products, defecation to remove residues. Organ Major Functions Other Functions Mouth Ingests food; Mechanical chewing of food; Salivary amylase begins chemical breakdown of starch; Swallows food and propels it into pharynx Salivary mucus Pharynx Propels bolus from oral cavity to esophagus Mucus lubricates food passageways Esophagus Peristaltic waves propel food bolus to stomach Mucus lubricates food passageways Stomach Peristaltic waves combine food withgastric juice and move it into theduodenum; Pepsin begins protein digestion; Absorbs some fat-soluble substances (e.g., alcohol, aspirin) Hydrochloric helps dissolve food; Release of flavors stimulates tastebuds allowing us to appreciate its taste; Saliva moistens food, and tongue helps create a bolus that can be swallowed; Saliva cleans and lubricates the teeth and oral cavity neutralizes ingested pathogens and stimulates protein-digesting enzymes; Mucus lubricates and protects the stomach; Intrinsic acid Organ Major Functions Other Functions allows vitamin B12 to be absorbed in intestines factor Small intestine Mixes contents with digestive juices for digestion and absorption;Brush-border enzymes digest food; Absorbs breakdown products of carbohydrates, protein, fat, and nucleic acid digestion, along with vitamins, water, and electrolytes Alkaline mucus helps Large intestine Enteric bacteria digest some food residue and vitamins; Absorbs most residual water, electrolytes, and vitamins produced by enteric bacteria; Propels feces toward rectum; Defecation reflex eliminates feces Residues are concentrated and temporarily stored prior to defecation; Mucus smoothes passage of feces through colon neutralize acidic chymefrom the stomach Organ Major Functions Other Functions Accessory organs Liver: produces bile; Gall bladder: stores and concentrates bile; Pancreas: produces enzymes that digests food Gall bladder releases bile, which emulsifies fat and stimulates the digestion of fat and the absorption of fatty acids, monoglycerides, cholesterol, phospholipids, and fat-soluble vitamins; Bicarbonaterich pancreatic juice helps neutralize acidic chyme (from the stomach) and provide optimal environment for enzymatic activity