flow of food through digestive system
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Answers:Sorry... This is kinda long, because it's very detailed. This is the general idea of the complete digestion in the body. In this case, just subsitute 'pizza' in it. The Mouth: ----------------------------------- The process of mechanical digestion begins as you take your first bite of food. Your teeth carry out the first stage of mechanical digestion. Your centre teeth/incisors, cut the food into bit-sized pieces. On either side of the incisors are sharp and pointy teeth called canines. These teeth tear and slash the food in your mouth into smaller pieces. Behind the canines are the premolars and molars, which crush and grind the food. As the teeth do their work, saliva mixes with the pieces of food, moistening them into one slippery mass. When you eat a candy, it tastes sweet. It does because a chemical in the saliva has broken down the starch in the candy into sugar molecules. The breakdown of complex molecules into simpler ones-has taken place. This is called chemical digestion, and it is accomplished by enzymes.[A protein that speeds up chemical reactions in the body] ----------------------------------- The Esophagus: ----------------------------------- As you swallow, muscles in your throat move the food downward. While this happens, a flap of tissue called the epiglottis seals off your windpipe, preventing the food from entering. After that, food goes into the esophagus, a muscular tube that connects the mouth to the stomach. The esophagus is lined with mucus. Mucus is a thick, slippery substance produced by the body. Food only remains in the esophagus for about 10seconds. After food enters the esophagus, contractions of smooth muscles push the food toward the stomach. These involuntary waves of muscle contraction are called peristalsis. -------------------------------------- The Stomach: -------------------------------------- Food enters the stomach after it leaves the esophagus. Stomach is a J-shaped, muscular pouch located in the abdomen. As you eat, your stomach ach expands to hold all of the food that you swallow. An average adult's stomach holds about 2-2.5 litres of food. Three strong layers of muscle contract to produce a churning motion. This action squeezes the food, mixing it with fluids. The churning of the stomach mixes food with digestive juice, a fluid produced by cells in the lining of the stomach. Digestive juice contains the enzyme pepsin that breaks down proteins in your food into amino acids. Hydrochloric acid keeps the stomach functioning properly: keeping the stomach an acidic environment 1. Pepsin works best in an acidic environment. 2. This very strong acid kills many bacteria that you swallow along with your food. Food remains in the stomach until all of the solid material has been broken down into liquid form. Proteins will be chemically digested into chains of amino acids. The food, now a thick liquid, is released into the next part of the liquid, is released into the next part of the digestive system That is where final chemical digestion and absorption will take place. -------------------------------------- The Small Intestine: -------------------------------------- After the thick liquid leaves the stomach, it enters the small intestine. It is at about 6metres. It makes up 2/3 of the digestive system. It is called 'The SMALL Intestine' because it has a small diameter It is only about 2-3 centimetres wide. As the liquid moves into the small intestine, it mixes with enzymes and secretions. They are produced by 3 different organs The small intestine, the liver, and the pancreas. The liver and the pancreas deliver their substances to the small intestine through small tubes. The liver produces bile which breaks up the fat particles. Bile flows into the gallbladder, storing bile until the small intestine needs it.[Bile is not an enzyme, because it doesn't chemically digest foods. It breaks up large fat particles into smaller droplets] The droplets will be digested by enzymes produced by the pancreas. The small nutrient molecules are ready to be absorbed by the body. Millions of tiny finger-shaped structures absorb nutrient molecules. Nutrients pass from cells on the surface of a villus into blood vessels. -------------------------------------- The Large Intestine: -------------------------------------- By the time material reaches the end of the small intestine, most nutrients have been absorbed. The remaining material moves from the S.I. into the L.I.. The large intestine is the last section of the digestive system. It is about 1&1/2metres long. The L.I. contains bacteria feeding on the material passing through. The bacteria normally do not cause disease. They are actually helpful because they make certain vitamins, including vitamin K. The material entering the L.I. contains water and undigested food such as fibre. As the material moves through the L.I., water is absorbed into the bloodstream. The remaining material is readied for elimination from the body. ------------------------------- The large intestine ends in a short tube called the rectum. Here waste material is compressed into a solid form. This material is eliminated from the body through the anus, a muscular opening at the end of the rectum. ------------------------------ :)
Answers:1. IN THE MOUTH - it is chewed (mastication - mechanical digestion) - the enzyme amylase in the saliva breaks down the carbohydrates into smaller sugars 2. IN THE OESOPHAGUS - muscle contractions called peristalsis moves the food to the stomach 3. IN THE STOMACH - The smooth muscle of the stomach churn, mix and pummel the food - Gastric juices contain the following: 1. HCl 2. Renin 3. Pepsinogen - the inactive form of pepsin (which breaks down proteins into peptides) 4. Gastric Amylase 5. Gastric Lipase 4. SMALL INTESTINE - the main parts are (in order): the duodenum, jejunum and ileum - in the duodenum (the first part of the small intestine) bile and pancreatic juices are secreted. Bile (which is sent from the gall bladder) breaks down fats. Pancreatic juice contains many types of enzyme for many different functions, they are: 1. Trypsinogen 2. Chymotrypsin 3. Steapsin (Pancreatic Lipase) 4. Carboxypolypeptidase 5. Pancreatic Amylase - Using segmentation, the small intestine mixes the partly digested cheeseburger - Peristalsis contractions move the food along the small intestines 5. LARGE INTESTINES - The main parts are: the cecum, ascending colon, transverse colon, descending colon, sigmoid colon - Nothing is secreted here 6. RECTUM 7. ANAL CANAL 8. ANUS Wasn't sure how detailed you wanted the answer so if you need to know the functions of all the enzymes are heres a good website: http://www.biology-online.org/articles/digestive_enzymes.html Hope this helps :)
Answers:Digestion is the breaking down of foodstuffs in the body into a form that can be absorbed and used or excreted. It is also the process by which the body breaks down food into smaller components that can be absorbed by the blood stream,digestion begins when saliva is produced in the mouth and digestive enzymes are produced in the stomach.. The stomach continues to break food down mechanically and chemically through the churning of the stomach and mixing with enzymes. Absorption occurs in the stomach and gastrointestinal tract, and the process finishes with excretion. you can find it more with diagrams on these sites..
Answers:As carnivores that kill and feed entirely on the flesh of other mammals, tigers have short, powerful jaws with large jaw muscles. They have 30 teeth, 15 on each side of the jaw. Tigers use their large piercing canines to grab and kill prey. Their scissor-like molars slice flesh, and small incisors scrape meat from bones. Like all cats, tigers have a simple digestive system designed to process meat so that the nutrients can be readily absorbed into the bloodstream. MOUTH - The tigers jaw contains incisors, canines and molar teeth in both jaws, and the molars are ridged. The jaw moves up and down. This fact, together with the ridging of the molars indicates that they are used for tearing or crushing to brake down the foodstuffs. The salivary glands serve merely to lubricate, and do not have an important digestive function. STOMACH - The stomach serves two purposes. Firstly it is a reservoir. Although relatively small compared to the tigers size, this is all that is needed, as the food of a carnivore, wholly of meat and fat, is nutrient dense, allowing one small meal to suffice for many hours. The second function of the stomach is to subject the food to concentrated solution of hydrochloric acid, which dissolves and liquefies it. Only food that is dissolved can be digested. Different foods dissolve at different rates and leave the stomach at different rates. The ones that cannot be digested - raw vegetable matter, cellulose and bone - pass right through the animal unchanged, those that are too big to pass into the small intestine are vomited. So far very little digestion has taken place and, in the carnivore, the stomach is not an essential organ. THE SMALL INTESTINE -The small intestine is vitally important. Without it, no digestion could take place and the tiger could not survive. The dissolved food, called 'chyme' at this stage, leaves the stomach in a series of spurts, controlled by a valve, the pylorus, and enters the small intestine. It is in the small intestine that food is digested and enters the bloodstream. After a few inches, two ducts connect from the pancreas and the liver to the small intestine. These two organs supply and deliver the enzymes needed to break down the fats and proteins into their component fatty acids and amino acids. Only in this form can they pass through the gut wall into the bloodstream. These enzymes are vitally important to the carnivore. Those from the pancreas immediately start to break down the chyme into its basic components and continue to do this throughout the chyme's passage along the small intestine. The chyme is a watery mixture but fat will not mix with water so it requires some special handling. This is where bile comes in. Bile is manufactured in the liver and stored in the gall bladder until such time as it is needed. When fat is detected in the small intestine, this triggers the release of the stored bile, which enters the intestine through the bile duct. Bile acts just like a detergent in that it emulsifies the fat to make it soluble in water. This action makes fat susceptible to digestion by the digestive enzymes. In the carnivore there are large amounts of fat in diet on occasion and, as bile is so important, its waste is not allowed. The liver makes bile continuously, the excess being diverted to the gall bladder to be saved and concentrated until it is needed (for the next meal). When a hormone in the upper gut signals that fat is again present in the gut, the stored bile is forcibly ejected to perform its function. Digestion of food in a carnivore is performed by enzymes produced by glands in the animal's own body and all the absorption of nutrients in that food is through the wall of the small intestine. The digestion of protein and fat, with little or no carbohydrate, in the carnivore's gut is remarkably efficient. Experiments which have measured the amounts of various nutrients eaten and compared these with the amounts passed in the animal's excreta have shown that a healthy animal loses no more than four percent of its fat intake and only a trace of the protein. As there is no enzyme in the carnivore capable of digesting cellulose, the material that the cell walls of all plants are composed, little or no digestion of carbohydrates can take place. THE CAECUM - the small intestine doesn't join the large intestine in a straight line, but at a right angle. At this point is a small appendage, two or three inches in length, called the caecum. While this has no functional use in a carnivore so it is usually very small. THE LARGE INTESTINE - By the time the chyme has passed through the tiger s small intestine, the process of digestion and absorption of the nutrients in the food is complete. The large intestine, or colon , has just one function to perform. It would be wasteful to allow water to escape and so the colon extracts the water and compacts the rest of the waste material from what is left of the chyme into a small compact mass, where it is stored in the rectum until it is finally expelled through the anus. The colon in a carnivore is not essential, merely a convenience. THE GUT FLORA - Practically the whole of the gastrointestinal tract of a carnivore is sterile. The hydrochloric acid in the stomach ensures that most bacteria and other micro-organisms in swallowed food are killed. Those that escape the stomach are rarely able to survive the digestive processes - they are, after all, made of protein. The colon is the exception. This, where no further digestive processes occur, does tend to harbour a variety of organisms which form certain vitamins such as pyridoxine, vitamin B-12, biotin, vitamin K and folic acid but, as these are not absorbed through the wall of the colon, they are of little account. These micro-organisms thrive in an alkaline environment and are of the putrefactive type. THE LENGTH OF THE GASTROINTESTINAL TRACT - It is generally reckoned that the total length of a carnivore's gut is probably about five to six times the length of the animal's body. DIET -Tigers are meat eaters (carnivores). Their prey includes small- to medium-sized mammals (like badgers, rabbits, boars, deer, and wild cattle), ranging in size from 60 to 2,000 pounds. The usual method of killing is to ambush the animal from behind and bite its neck; this usually breaks the prey's spinal cord, killing it. Tigers then drag the kill to a safe place in which they eat it. Tigers can eat as much as 40 pounds of meat in one sitting. They can go for days at a time without eating. -In the wild, tigers mostly feed on deer, wild boar, and wild cattle, including gaur and water buffaloes, young rhinos and young elephants, and sometimes, even leopards and bears. Tigers have been known to kill crocodiles on occasion. CHEMICAL COMPOSITION (wild boars meat) Wild boars meat possesses profitable chemical composition as a raw material of high content of protein and low content of fat. Considerable protein content equal to 21.80% Examined meat also contained large quantities of water 74.25% low content of fatty components 1.95%