The bile salts’ hydrophilic side can interface with water, while the hydrophobic side interfaces with lipids, thereby emulsifying large lipid globules into small lipid globules. The next step of carbohydrate digestion takes place in the duodenum.
After the fat is dissolved, it is digested by enzymes from the pancreas and the lining of the intestine. The ileocecal valve is a one-way valve located between the ileum and the cecum, which is the first portion of the colon.
Oral stage of digestion
Food is the body’s source of fuel. Nutrients in food give the body’s cells the energy they need to operate.
Inside this tube is a lining called the mucosa. In the mouth, stomach, and small intestine, the mucosa contains tiny glands that produce juices to help digest food.
Ducts from the gall bladder and pancreas feed fluids rich in bile salts and digestive enzymes into the duodenum. In addition, some of the cells lining the small intestine produce a fluid known as ‘succus entericus’ made up mostly of water, mucus and sodium bicarbonate. Visit this site for an overview of digestion of food in different regions of the digestive tract. Note the route of non-fat nutrients from the small intestine to their release as nutrients to the body.
An alternative to the jejunostomy tube is parenteral nutrition, in which nutrients are delivered directly into the bloodstream, bypassing the digestive system. The physician places a catheter in a chest vein, leaving an opening on the outside of the skin. A bag with liquid nutrients or medication can be attached to the catheter, allowing the fluid to enter the bloodstream through the vein. Gastroparesis slows and disrupts the timing of food absorption.
Herbivores’ teeth are made for grinding plants and other food to ease them through the digestion process. Produces enzymes that break down all categories of digestible foods, including proteins, carbohydrates, and fats. Mechanical and chemical processes that break food down into simple ,molecules. The presence of a digestive enzyme, known as amylase, in saliva allows chemical digestion of starches to begin.
As protein enters the stomach, it binds to hydrogen ions, which raises the pH of the stomach. Inhibition of gastrin and gastric acid secretion is lifted. This triggers G cells to release gastrin, which in turn stimulates parietal cells to secrete gastric acid. Digesta is finally moved into the small intestine, where the digestion and absorption of nutrients occurs.
Watery stools that resule when food residue is rushed through the large intestine before sufficient water has been reabsorbed, causing dehydration and electrolyte imbalance is called constipation. Proteins are broken down into building blocks known as amino acids by the digestive system. Peyer’s patches associates with the small intestine prevent overwhelming amounts of bacteria from entering the blood stream. Instrinsic factor, produced by cells in the stomach, is necessary for the absoprtion of vitamin ————- in the small intestine. parenteral nutrition.
The liver can also metabolize the short-chain fatty acids into cellular energy. The yield of energy from dietary fiber is about 2 kilocalories per gram for humans but is highly dependent upon the fiber type, with soluble fibers and resistant starches yielding more energy than insoluble fibers. Since dietary fiber is digested much less in the gastrointestinal tract than other carbohydrate types (simple sugars, many starches) the rise in blood glucose after eating them is less, and slower. These physiological attributes of high-fiber foods (i.e. whole grains) are linked to a decrease in weight gain and reduced risk of chronic diseases, such as Type 2 diabetes and cardiovascular disease. The digestive system is made up by the alimentary canal, or the digestive tract, and other abdominal organs that play a part in digestion such as the liver and the pancreas.
Most digestive enzymes are sensitive to pH and will denature in a high or low pH environment. Some organisms, including nearly all spiders, simply secrete biotoxins and digestive chemicals (e.g., enzymes) into the extracellular environment prior to ingestion of the consequent “soup”.
But sometimes a bacteria called Helicobacter pylori or the chronic use of drugs or certain medications, weakens the mucous layer that coats the stomach and the duodenum, allowing acid to get through the sensitive lining beneath. This can cause irritation and inflammation of the lining of the stomach, which is called gastritis, or cause peptic ulcers, which are holes or sores that form in the lining of the stomach and duodenum and cause pain and bleeding. Medications are the best way to treat this condition.
Movement of Food Through the System
In most people, the stomach mucosa is able to resist the juice, although food and other tissues of the body cannot. Finally, all of the digested nutrients are absorbed through the intestinal walls. The waste products of this process include undigested parts of the food, known as fiber, and older cells that have been shed from the mucosa. These materials are propelled into the colon, where they remain, usually for a day or two, until the feces
admin September 27, 2009