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Reverse Soft Tissue Calcification: Bring Calcium Out Of Tissue \u0026 Into BonesNutrient absorption in the bloodstream -
Digestive system explained. Actions for this page Listen Print. Summary Read the full fact sheet. On this page. The mouth and oesophagus The stomach The small intestine Pancreas Liver The large intestine Common problems in the digestive system Where to get help.
The mouth and oesophagus Digestion begins in the mouth. The stomach The food passes through a sphincter, or small muscle ring, into the stomach.
The small intestine Once in the duodenum, the food is mixed with more digestive enzymes from the pancreas and bile from the liver.
Pancreas The pancreas is one of the largest glands in the human body. Liver The liver has a number of different roles in the body, including: breaking down fats, using bile stored in the gall bladder processing proteins and carbohydrates filtering and processing impurities, drugs and toxins generation of glucose for short-term energy needs from other compounds like lactate and amino acids.
The large intestine Once all the nutrients have been absorbed, the waste is moved into the large intestine, or bowel. Common problems in the digestive system Some common problems include: colitis — inflammation of the bowel diverticulitis — inflammation of pouches lining the small intestine gastroenteritis — an infection that causes vomiting and diarrhoea heartburn — when the contents of the stomach back up into the oesophagus ulcer — a hole in the mucous membrane lining the stomach or duodenum.
Where to get help Your doctor. Give feedback about this page. Was this page helpful? Yes No. Related information. From other websites External Link Gastroenterological Society of Australia GESA. Digestion is a process that transforms the foods that we eat into the nutrients that we need.
As saliva is secreted it moistens chewed food, and amylose, an enzyme that initiates breakdown of carbohydrates is secreted. Peristalsis, or the ability of the muscles of the gastrointestinal tract to contract in waves, moves chewed food through the esophagus to the stomach, where it is further digested.
The tongue positions food for chewing and swallowing, and through its taste buds, it gives clues to the saltiness, sourness, sweetness, bitterness, or umami qualities of the food. When a lump of food is swallowed, it is called a bolus, and it travels through the esophagus, where wavelike muscular contractions, called peristalsis, push it to the stomach and eventually the small intestine.
The esophagus is a muscular tube that connects the mouth to the stomach. As the esophagus and trachea share a common pathway, a flap of tissue called the epiglottis closes off the trachea when you swallow.
Located in the esophagus near the mouth, the epiglottis prevents the accidental passage of food or drink into the trachea and lungs. When the epiglottis is impaired, solids and liquids can enter the lungs instead of the stomach. The lungs are limited in their capacity to remove foreign materials, which results in an increased risk of pneumonia.
Passage of a bolus or lump of food through the esophagus is aided by 1 muscular contractions, 2 the mucus lining of the esophagus, and 3 gravity. After eating, you can take advantage of the pull of gravity by staying upright in a standing or sitting position.
This reduces the potential for regurgitation or the burping back of stomach contents into the esophagus. At the lower portion of the esophagus is a thick circle of muscles known as the lower esophageal sphincter LES.
After peristalsis forces a bolus of food through the LES and into the stomach, it reverts to its closed position, preventing regurgitation back into the esophagus.
Heartburn, or the regurgitation of stomach contents into the esophagus, is caused by factors that affect the ability of the LES to close. Eating or drinking more than the stomach can comfortably handle is one cause.
Another is lying down after a large meal. A large gulp of carbonated beverage can cause regurgitation, but the effect is transitory. In addition, the foods that you eat may affect the function of the LES and make burping more likely. A reduced LES pressure, or tone, reduces its ability to tightly constrict and increases the likelihood that you will regurgitate or burp.
Some foods are known to affect tone; for example, foods high in sugars and starches, both carbohydrates, increase the likelihood of regurgitation, while dietary fiber, also a carbohydrate, decreases the frequency of regurgitation and heartburn.
Although people sometimes say that there is a relationship between dietary fats and heartburn, one has yet to be found in a comprehensive study such as the National Health and Nutrition Examination Survey. While acidic or spicy foods can irritate the lining of the esophageal, they are not thought to contribute to regurgitation.
Food and beverages that lower pressure include peppermint, spearmint, chocolate, alcohol, and coffee. Consumption of these foods encourages regurgitation because the sphincter does not close tightly enough after swallowing.
A small meal size, limiting consumption of sugars and starches, and avoiding late-night eating are recommended practices to reduce the likelihood of regurgitation and heartburn. The mucus layer lining the esophagus serves to lubricate a passing bolus of food, but the thicker mucus layer that lines the stomach has a different task.
It provides a continuous barrier that protects the stomach from the corrosive effects of enzymes and acids that would damage unprotected stomach cells. An example is the digestion of protein that begins in the stomach as pepsinogen is converted to the active form pepsin.
Without the protection of the mucus layer, stomach cells exposed to pepsin would be damaged, resulting in sores in the stomach lining or an ulcer.
When there is a breakdown in the thick mucus layer protecting the stomach lining from the caustic effects of acid and pepsin, gastric ulcers may result. Stomach pain and bleeding that comes and goes is a sign that underlying tissue is damaged.
Genetics, stress, smoking, and the long-term use of nonsteroid anti-inflammatory drugs like aspirin or ibuprofen are among the factors that contribute to ulcer development. Sometimes a peptic ulcer is caused when the mucous coating of the stomach is damaged by infection by Helicobacter pylori H.
pylori is a bacteria that is transmitted person to person oral-oral route through saliva or vomit as well as through water that is contaminated with feces oral-fecal route.
Antibiotics are effective in treating ulcers where a chronic infection with a bacterial infection is the causative factor. pylori bacteria are spread through close contact and exposure to vomit.
Help stop the spread of H. pylori by washing your hands! Treatment of ulcers may include stress-reduction techniques and antacids to counteract stomach secretions and reduce pain. It is a good idea to stop smoking and reduce alcohol consumption as well. The stomach is a J-shaped pouch positioned between the esophagus and the small intestine.
It is grapefruit sized and expands when filled. It churns and mixes food received from the esophagus. When stimulated by the presence of food or drink, the stomach secretes hydrochloric acid, which lowers contents to a pH of less than two, creating an acidic environment. This activates the enzyme pepsinogen, converting it to pepsin, which begins the digestion of protein.
It also denatures or uncoils protein molecules, making it easier for pepsin to work. How acidic are stomach contents? Consider that vinegar has a pH of two; grapefruit juice, three; black coffee, five; distilled water neutral , seven; and baking soda alkaline , nine.
This highly acidic environment discourages bacterial growth and helps in the prevention of bacterial diseases, such as foodborne illness. Endocrine cells in the stomach produce gastrin, somatostatin, and ghrelin, which are hormones that help regulate stomach function.
Gastrin regulates gastric acid production and stimulates appetite. Conversely, somatostatin counteracts gastrin and reduces its production when a meal is over and eating more food is not imminent.
Although ghrelin is sometimes called the hunger hormone, its role goes beyond stimulating appetite. The ability of your stomach to expand, or its capacity, is related to the amount of food that you routinely eat at one sitting.
In most cases, stomach capacity is about thirty-two to forty-six ounces. People who habitually overeat have larger stomach capacities than they would if they ate smaller portions.
While the stomach does not shrink, making a habit of eating smaller amounts tightens stomach muscles and reduces the overall ability to stretch.
As a result, stretching sensors that signal that the stomach is full are activated at a smaller capacity when fewer calories have been consumed. After mixing is complete, the stomach moves food and gastric secretions to the small intestine in a watery solution called chyme.
Stomach muscles contract in waves to squirt chyme through the pyloric sphincter, separating the stomach from the small intestine at a rate of one to five milliliters per thirty seconds, or about one to two teaspoons per minute. It takes two to four hours for a typical meal to pass completely into the small intestine.
The type of food or drink affects the rate of passage. Isotonic liquids, which have the same solute concentration as body cells, leave the stomach more quickly than hypertonic liquids or solids, which tend to spend the most time in the stomach.
A hypertonic liquid has a higher solute concentration than body cells or blood, while hypotonic liquid has a lower one. An example of an isotonic liquid is Gatorade or Powerade.
Sweetened, carbonated beverages are hypertonic, and water is hypotonic. Foods that are high in fat leave the stomach more slowly than foods high in either protein or carbohydrates. Fiber also reduces the rate at which gastric contents empty into the small intestine.
As a result, meals with adequate fiber depress the rate at which carbohydrates elevate blood glucose levels as well as prolong the sense of satisfaction or satiety generated by a full stomach.
By moderating the rate at which chyme passes into the small intestine, where carbohydrates are digested and absorbed. Overall, an additional three to ten hours is needed for your meal to traverse the large intestine and complete its journey.
An additional one to two days may pass before residues that are mostly fiber leave your body. Chewed food is swallowed as a lump, or bolus, which the muscles of the gastrointestinal tract push in a wavelike motion past the epiglottis, through the esophagus, and into the stomach.
Swallowing causes a temporary relaxation of the LES, which returns to a contracted state after the bolus passes into the stomach. Gastroesophageal reflux disease GERD happens when stomach contents pass back through the LES into the esophagus, causing heartburn and regurgitation.
GERD treatment includes behavioral modification and medications that reduce stomach acid content. The stomach continues the breakdown of foods that started with chewing. Hydrochloric acid in the stomach denatures food proteins, making them more digestible, and inhibits bacterial growth, which reduces the risk of foodborne illness.
Gastrin, somatostatin, and ghrelin manage stomach function, while pepsinogen is activated to make pepsin, which begins the enzymatic breakdown of protein. Stomach contractions move the mixture of food and gastric juices into the small intestine, where further digestion takes place.
The vast majority of the nutrients that we get from our food and drink are absorbed in the small intestine. An amazing list of hormones, enzymes, emulsifiers, and carrier molecules makes this possible.
Even though fat, carbohydrates, and protein are absorbed in the small intestine, much work remains for the large intestine, where fiber supports beneficial bacteria, water is conserved through absorption, and digestive residues are prepared for excretion. The small intestine is the primary site for the digestion and eventual absorption of nutrients.
In fact, over 95 percent of the nutrients gained from a meal, including protein, fat, and carbohydrate, are absorbed in the small intestine. Alcohol, an additional source of energy, is largely absorbed in the small intestine, although some absorption takes place in the mouth and stomach as well.
Three organs of the body assist in digestion: the liver, the gall bladder, and the pancreas. The liver produces bile, a substance that is crucial to the digestion and absorption of fat, and the gall bladder stores it. The pancreas provides bicarbonate and enzymes that help digest carbohydrates and fat.
The liver, gall bladder, and pancreas share a common duct into the small intestine, and their secretions are blended.
Along the way, food is broken down into tiny molecules so that the body can absorb nutrients it needs:. The digestive system is made up of the alimentary canal also called the digestive tract and other organs, such as the liver and pancreas.
The alimentary canal is the long tube of organs — including the esophagus, stomach, and intestines — that runs from the mouth to the anus.
An adult's digestive tract is about 30 feet about 9 meters long. Digestion begins in the mouth, well before food reaches the stomach. When we see, smell, taste, or even imagine a tasty meal, our salivary glands in front of the ear, under the tongue, and near the lower jaw begin making saliva spit.
As the teeth tear and chop the food, spit moistens it for easy swallowing. A digestive enzyme in saliva called amylase pronounced: AH-meh-lace starts to break down some of the carbohydrates starches and sugars in the food even before it leaves the mouth.
Swallowing, done by muscle movements in the tongue and mouth, moves the food into the throat, or pharynx pronounced: FAIR-inks.
The pharynx is a passageway for food and air. A soft flap of tissue called the epiglottis pronounced: ep-ih-GLAH-tus closes over the windpipe when we swallow to prevent choking. From the throat, food travels down a muscular tube in the chest called the esophagus pronounced: ih-SAH-fuh-gus.
Waves of muscle contractions called peristalsis pronounced: per-uh-STALL-sus force food down through the esophagus to the stomach. A person normally isn't aware of the movements of the esophagus, stomach, and intestine that take place as food passes through the digestive tract.
At the end of the esophagus, a muscular ring or valve called a sphincter pronounced: SFINK-ter allows food to enter the stomach and then squeezes shut to keep food or fluid from flowing back up into the esophagus.
The stomach muscles churn and mix the food with digestive juices that have acids and enzymes, breaking it into much smaller, digestible pieces. An acidic environment is needed for the digestion that takes place in the stomach. By the time food is ready to leave the stomach, it has been processed into a thick liquid called chyme pronounced: kime.
A walnut-sized muscular valve at the outlet of the stomach called the pylorus pronounced: pie-LOR-us keeps chyme in the stomach until it reaches the right consistency to pass into the small intestine.
Chyme is then squirted down into the small intestine, where digestion of food continues so the body can absorb the nutrients into the bloodstream.
The digestive system is agsorption up of the gastrointestinal Nutrient absorption in the bloodstream called the GI tract or digestive rhe the liver Citrus aurantium for cholesterol management, pancreasand gallbladder. The Ln tract is a Nutrient absorption in the bloodstream of hollow organs joined in a long, twisting tube from the mouth to the anus. The hollow organs that make up the GI tract are the mouth, esophagusstomach, small intestine, large intestine, and anus. The liver, pancreas, and gallbladder are the solid organs of the digestive system. The small intestine has three parts. The first part is called the duodenum. Fhe you have learned, the process of mechanical digestion is relatively absorpion. It bliodstream the physical breakdown of food but does not alter its chemical makeup. Chemical digestion, on the other hand, is a complex process that reduces food into its chemical building blocks, which are then absorbed to nourish the cells of the body. In this section, you will look more closely at the processes of chemical digestion and absorption. Figure 1.
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