Digestion and Important Functions

frame of reference &Physiology Digestion is the process by which fare is broken down into scummyer pieces so that the body can white plague them to build andnourish cells and to provide energy. Digestion involves the struting of food, its movement through thedigestive pathway (also known as the alimentary canal), andthe chemical breakdown of plumpingr molecules intosmaller molecules. Everypiece of food we eat has tobe broken down into smaller nutrients that the body can absorb, which is why it takes hours to fully digest food. The digestive placement is made up of the digestive tract.This consists of a long underground oforgans that runs from the mouth to the anus and includes the esophagus, stomach, small intestine, and large intestine, together with the liver, gallbladder, andpancreas, whichproduce crucial secretions for digestion that drain into the small intestine. The digestive tract in an adult is about 30feet long. Mouth and spitry Glands Digestion begins inthe mout h, where chemical and mechanical digestion occurs. Saliva or spit, producedby the salivary glands (located underthe tongue and near the lowerjaw), is released into the mouth.Saliva begins to break down the food, moisten it and making it easier toswallow. A digestive enzyme(called amylase) in the saliva begins to breakdown the carbohydrates(starches and sugars). One of the most strategic functions of the mouth ischewing. Chewing allows food to be mashed into a soft mass that is easier to swallow and digest later. defile Once food is swallowed, it enters the esophagus, a brawny tube that is about10 inches long. The esophagus is located between the throat and the stomach. powerfulwavelike contractions known as peristalsis push the food down throughthe esophagus to the stomach.A muscular ring (called the cardiac sphincter) at the end of the esophagus allows food to enter the stomach, and, then, itsqueezes shut to prevent food and fluid from going back up the esophagus. Stomach a J-shaped organt hat lies between the esophagus and the small intestine in the upperabdomen. The stomach has 3 master(prenominal) functions tostore the swallowed food and liquid to mix up the food,liquid, and digestive juices produced by the stomach and to slowly empty its contents into thesmall intestine. Small gut Most digestion and tightness of food occurs in the small intestine.The small intestine is a narrow,twisting tube that occupies most ofthe lower abdomen between the stomach and the bloodline of the largeintestine. It extends about 20 feet in length. The small intestine consists of 3 parts the duodenum (the C-shaped part), thejejunum(the coiled midsection), and the ileum(the last section). The smallintestine has 2 important functions. First, the digestive process is completed hereby enzymes and other substances made by intestinal cells, the pancreas, andthe liver. Glands in theintestine walls secrete enzymes that breakdown starches and sugars.The pancreas secretes enzy mes into thesmall intestine that helpbreakdown carbohydrates, fats, and proteins. The liver producesbile, which is stored in the gallbladder. impertinence helps to make fat molecules (which otherwise arenot soluble in water) soluble, so they can be preoccupied bythe body. Second, the small intestine absorbs the nutrients from the digestive process. The inner wall of the small lintestine is c overed by millions oftiny fingered projections called villi. The villi are covered with even tinier projections called microvilli.Thecombination of villi and microvilli increase the surface area ofthe small intestine greatly, allowing absorption ofnutrients to occur. Undigested material travels nextto the large intestine. Large intestine forms an upside down U overthe coiled small intestine. It begins at the lower right-hand side of the body and endson the lower left-hand(prenominal) side. The large intestine is about 5-6 feet long. Ithas 3 parts the cecum, the colon, and the rectum. The ce cum is apouch at the beginning of thelarge intestine. This area allows food to pass from the small intestine to the large intestine.The colon is where fluids and salts are absorbed and extends from the cecum to the rectum. Thelast part of the large intestine is the rectum, which is where feces( eat up material) is stored before leaving the body through the anus. The mainjob of the large intestine is toremove water and salts (electrolytes) from the undigested material and to form solid waste that can be excreted. Bacteria in the large intestine help tobreak down theundigested materials. The remaining contents of thelarge intestine are moved toward the rectum, where feces are stored until they leave the body through the anus as abowel movement.