query: where does mechanical digestion take place in the human digestive system

pos: Digestion small molecules the body can use. In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact of saliva. Saliva, a liquid secreted by the salivary glands, contains salivary amylase, an enzyme which starts the digestion of starch in the food; the saliva also contains mucus, which lubricates the food, and hydrogen carbonate, which provides the ideal conditions of pH (alkaline) for amylase to work. After undergoing mastication and starch digestion, the food will be in the form of a

pos: Human digestive system Human digestive system The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has many stages. The first stage is the cephalic phase of digestion which begins with gastric secretions in response to the sight and smell of food. The next stage starts in the mouth. Chewing, in which food is mixed with saliva, begins the mechanical process of digestion. This produces

pos: Digestion small molecules the body can use. In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact of saliva. Saliva, a liquid secreted by the salivary glands, contains salivary amylase, an enzyme which starts the digestion of starch in the food; the saliva also contains mucus, which lubricates the food, and hydrogen carbonate, which provides the ideal conditions of pH (alkaline) for amylase to work. After undergoing mastication and starch digestion, the food will be in the form of a

pos: Digestion cephalic phase in which saliva is produced in the mouth and digestive enzymes are produced in the stomach. Mechanical and chemical digestion begin in the mouth where food is chewed, and mixed with saliva to begin enzymatic processing of starches. The stomach continues to break food down mechanically and chemically through churning and mixing with both acids and enzymes. Absorption occurs in the stomach and gastrointestinal tract, and the process finishes with defecation. The human gastrointestinal tract is around 9 meters long. Food digestion physiology varies between individuals and upon other factors such as the characteristics of the food and

pos: Human digestive system blood in the colon of the large intestine. The waste products of digestion (feces) are defecated from the anus via the rectum. There are several organs and other components involved in the digestion of food. The organs known as the accessory digestive glands are the liver, gall bladder and pancreas. Other components include the mouth, salivary glands, tongue, teeth and epiglottis. The largest structure of the digestive system is the gastrointestinal tract (GI tract). This starts at the mouth and ends at the anus, covering a distance of about nine (9) metres. The largest part of the GI tract is

pos: Human digestive system a bolus which can be swallowed down the esophagus to enter the stomach. Here it is mixed with gastric acid until it passes into the duodenum where it is mixed with a number of enzymes produced by the pancreas. Saliva also contains a catalytic enzyme called amylase which starts to act on food in the mouth. Another digestive enzyme called lingual lipase is secreted by some of the lingual papillae on the tongue and also from serous glands in the main salivary glands. Digestion is helped by the chewing of food carried out by the muscles of mastication, by the

pos: Digestion size of the meal, and the process of digestion normally takes between 24 and 72 hours. Digestion begins in the mouth with the secretion of saliva and its digestive enzymes. Food is formed into a bolus by the mechanical mastication and swallowed into the esophagus from where it enters the stomach through the action of peristalsis. Gastric juice contains hydrochloric acid and pepsin which would damage the walls of the stomach and mucus is secreted for protection. In the stomach further release of enzymes break down the food further and this is combined with the churning action of the stomach.

pos: Extracellular digestion initial components of the gastrointestinal tract are the mouth and the pharynx, which is the common passage of the oral and nasal cavities. The pharynx leads to the esophagus, a muscular tube that delivers food to the stomach, where some preliminary digestion occurs; here, the digestion is extracellular. From the stomach, food passes to the small intestine, where a battery of digestive enzymes continue the digestive process. The products of digestion are absorbed across the wall of the intestine into the bloodstream. What remains is emptied into the large intestine, where some of the remaining water and minerals are absorbed;

pos: Chyme will be absorbed along with other nutrients. Chyme has a low pH that is countered by the production of bile, helping to further digest food. Chyme is part liquid and part solid: a thick semifluid mass of partially digested food and digestive secretions that is formed in the stomach and small intestine during digestion. Chyme also contains cells from the mouth and esophagus that slough off from the mechanical action of chewing and swallowing. After hours of mechanical and chemical digestion, food has been reduced into chyme. As particles of food become small enough, they are passed out of the

pos: Insect mouthparts (element 32 in numbered diagram) the insect can mix its food with saliva. The mixture of saliva and food then travels through the salivary tubes into the mouth, where it begins to break down. Some insects, like flies, have extra-oral digestion. Insects using extra-oral digestion expel digestive enzymes onto their food to break it down. This strategy allows insects to extract a significant proportion of the available nutrients from the food source. The gut is where almost all of insects' digestion takes place. It can be divided into the foregut, midgut and hindgut. The first section of the alimentary

pos: Human digestive system moistens and softens food, and along with the chewing action of the teeth, transforms the food into a smooth bolus. The bolus is further helped by the lubrication provided by the saliva in its passage from the mouth into the esophagus. Also of importance is the presence in saliva of the digestive enzymes amylase and lipase. Amylase starts to work on the starch in carbohydrates, breaking it down into the simple sugars of maltose and dextrose that can be further broken down in the small intestine. Saliva in the mouth can account for 30% of this initial starch digestion. Lipase

pos: Insect morphology saliva. The mixture of saliva and food then travels through the salivary tubes into the mouth, where it begins to break down. Some insects, like flies, have extra-oral digestion. Insects using extra-oral digestion expel digestive enzymes onto their food to break it down. This strategy allows insects to extract a significant proportion of the available nutrients from the food source. Once food leaves the crop, it passes to the midgut (element 13 in numbered diagram), also known as the mesenteron, where the majority of digestion takes place. Microscopic projections from the midgut wall, called microvilli, increase the surface area of

pos: Digestion (largely the glucose-insulin system) have been uncovered in recent years. Digestion is a complex process controlled by several factors. pH plays a crucial role in a normally functioning digestive tract. In the mouth, pharynx and esophagus, pH is typically about 6.8, very weakly acidic. Saliva controls pH in this region of the digestive tract. Salivary amylase is contained in saliva and starts the breakdown of carbohydrates into monosaccharides. Most digestive enzymes are sensitive to pH and will denature in a high or low pH environment. The stomach's high acidity inhibits the breakdown of carbohydrates within it. This acidity confers two

pos: Extracellular digestion three areas: the fore gut, mid gut, and hind gut. All free-living species exhibit a distinct and separate mouth and anus, and in all species, food must be moved through the digestive tract by muscular activity rather than cilia activity since the lumen of the fore gut and hind gut is lined with cuticle. Digestion is generally extracellular. Nutrients are distributed to the tissues through the hemal system. Most molluscs have a complete digestive system with a separate mouth and anus. The mouth leads into a short esophagus which leads to a stomach. Associated with the stomach are one or

pos: Shark function to excrete large amounts of urea. When a shark dies, the urea is broken down to ammonia by bacteria, causing the dead body to gradually smell strongly of ammonia. Digestion can take a long time. The food moves from the mouth to a J-shaped stomach, where it is stored and initial digestion occurs. Unwanted items may never get past the stomach, and instead the shark either vomits or turns its stomachs inside out and ejects unwanted items from its mouth. One of the biggest differences between the digestive systems of sharks and mammals is that sharks have much shorter

pos: Fish physiology food is further digested and, in many fish, processed in finger-shaped pouches called pyloric caeca, which secrete digestive enzymes and absorb nutrients. Organs such as the liver and pancreas add enzymes and various chemicals as the food moves through the digestive tract. The intestine completes the process of digestion and nutrient absorption. In most vertebrates, digestion is a four-stage process involving the main structures of the digestive tract, starting with ingestion, placing food into the mouth, and concluding with the excretion of undigested material through the anus. From the mouth, the food moves to the stomach, where as bolus it

pos: Planarian organ systems. The digestive system consists of a mouth, pharynx, and a gastrovascular cavity. The mouth is located in the center of the underside of the body. Digestive enzymes are secreted from the mouth to begin external digestion. The pharynx connects the mouth to the gastrovascular cavity. This structure branches throughout the body allowing nutrients from food to reach all extremities. Planaria eat living or dead small animals that they suck up with their muscular mouths. Food passes from the mouth through the pharynx into the intestines where it is digested by the cells lining the intestines. Then its nutrients

pos: Extracellular digestion food are engulfed into the vacuoles of the digestive cells for intracellular digestion. Any undigested and un-absorbed food is finally thrown out of the mouth. Single-celled organisms as well as sponges digest their food intracellularly. Other multi-cellular organisms digest their food extracellularly, within a digestive cavity. In this case the digestive enzymes are released into a cavity that is continuous with the animal's external environment. In cnidarians and in flatworms such as planarians, the digestive cavity, called a gastrovascular cavity, has only one opening that serves as both mouth and anus. There is no specialization within this type of digestive

pos: Human digestive system intestine. The mouth is the first part of the upper gastrointestinal tract and is equipped with several structures that begin the first processes of digestion. These include salivary glands, teeth and the tongue. The mouth consists of two regions; the vestibule and the oral cavity proper. The vestibule is the area between the teeth, lips and cheeks, and the rest is the oral cavity proper. Most of the oral cavity is lined with oral mucosa, a mucous membrane that produces a lubricating mucus, of which only a small amount is needed. Mucous membranes vary in structure in the different regions

pos: Human digestive system glycoprotein called haptocorrin which is a binding protein to vitamin B. It binds with the vitamin in order to carry it safely through the acidic content of the stomach. When it reaches the duodenum, pancreatic enzymes break down the glycoprotein and free the vitamin which then binds with intrinsic factor. Food enters the mouth where the first stage in the digestive process takes place, with the action of the tongue and the secretion of saliva. The tongue is a fleshy and muscular sensory organ, and the very first sensory information is received via the taste buds in the papillae on

neg: Human digestive system predispose for certain digestive disorders. Gestational diabetes can develop in the mother as a result of pregnancy and while this often presents with few symptoms it can lead to pre-eclampsia. Human digestive system The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has many stages. The first stage is the cephalic phase of digestion which begins with gastric secretions in response

neg: Extracellular digestion more digestive glands or digestive caeca. Digestive enzymes are secreted into the lumen of these glands. Additional extracellular digestion takes place in the stomach. In cephalopods, digestion is entirely extracellular. In the most other mollusks, the terminal stages of digestion are completed intracellularly, within the tissue of the digestive glands. The absorbed nutrients enter the circulatory system for distribution throughout the body or are stored in the digestive glands for later use. Undigested waste pass through an intestine and out through the anus. Other aspects of food collection and processing have already been discussed where appropriate for each group. The

neg: Digestion gizzard add enzymes to the thick paste, which helps chemically breakdown the organic matter. By peristalsis, the mixture is sent to the intestine where friendly bacteria continue chemical breakdown. This releases carbohydrates, protein, fat, and various vitamins and minerals for absorption into the body. In most vertebrates, digestion is a multistage process in the digestive system, starting from ingestion of raw materials, most often other organisms. Ingestion usually involves some type of mechanical and chemical processing. Digestion is separated into four steps: Underlying the process is muscle movement throughout the system through swallowing and peristalsis. Each step in digestion requires

neg: Digestive enzyme Digestive enzyme Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the traps of carnivorous plants, where they aid in the digestion of food, as well as inside cells, especially in their lysosomes, where they function to maintain cellular survival. Digestive enzymes of diverse specificities are found in the saliva secreted by the salivary glands, in the secretions of cells lining In the human digestive system, the main sites

neg: Digestive enzyme these enzymes include: Digestive enzyme Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the traps of carnivorous plants, where they aid in the digestion of food, as well as inside cells, especially in their lysosomes, where they function to maintain cellular survival. Digestive enzymes of diverse specificities are found in the saliva secreted by the salivary glands, in the secretions of cells lining In the human digestive system,

neg: Human digestive system the colon or large intestine. Water is absorbed here and the remaining waste matter is stored prior to defecation. Most of the digestion of food takes place in the small intestine. A major digestive organ is the stomach. Within its mucosa are millions of embedded gastric glands. Their secretions are vital to the functioning of the organ. There are many specialised cells of the GI tract. These include the various cells of the gastric glands, taste cells, pancreatic duct cells, enterocytes and microfold cells. Some parts of the digestive system are also part of the excretory system, including the large

neg: Mistletoebird important for reproduction and molting, the mistletoe bird has to eat large quantities of the mistletoe fruit. The mistletoebird has a small muscularized stomach and short alimentary canal where the amount of mechanical grinding and chemical digestion is minimized. This enables a clear passage and quick exit of the mistletoe fruit seeds through the mistletoebird's digestive system. In comparison, the non-specialized fruit eating birds that they compete with for the mistletoe berry, such as the spiny-cheeked honeyeater ("Acanthagenys rufogularis)" have a more complex digestive system that takes longer for the fruit seeds to pass and in the process the seeds

neg: Extracellular digestion here the digestion is intracellular. Extracellular digestion Extracellular digestion is a process in which saprobionts feed by secreting enzymes through the cell membrane onto the food. The enzymes catalyze the digestion of the food into molecules small enough to be taken up by passive diffusion, transport, or phagocytosis. Since digestion occurs outside the cell, it is said to be extracellular. It takes place either in the lumen of the digestive system, in a gastric cavity or other digestive organ, or completely outside the body. The prefix "extra" means "outside", and indicates that extracellular digestion must occur outside the cell. During

neg: Extracellular digestion Extracellular digestion Extracellular digestion is a process in which saprobionts feed by secreting enzymes through the cell membrane onto the food. The enzymes catalyze the digestion of the food into molecules small enough to be taken up by passive diffusion, transport, or phagocytosis. Since digestion occurs outside the cell, it is said to be extracellular. It takes place either in the lumen of the digestive system, in a gastric cavity or other digestive organ, or completely outside the body. The prefix "extra" means "outside", and indicates that extracellular digestion must occur outside the cell. During extracellular digestion, food is broken

neg: Human digestive system teeth, and also by the contractions of peristalsis, and segmentation. Gastric acid, and the production of mucus in the stomach, are essential for the continuation of digestion. Peristalsis is the rhythmic contraction of muscles that begins in the esophagus and continues along the wall of the stomach and the rest of the gastrointestinal tract. This initially results in the production of chyme which when fully broken down in the small intestine is absorbed as chyle into the lymphatic system. Most of the digestion of food takes place in the small intestine. Water and some minerals are reabsorbed back into the

neg: Human digestive system fats to some degree though is not as efficient as the pancreatic lipase. The pylorus, the lowest section of the stomach which attaches to the duodenum via the pyloric canal, contains countless glands which secrete digestive enzymes including gastrin. After an hour or two, a thick semi-liquid called chyme is produced. When the pyloric sphincter, or valve opens, chyme enters the duodenum where it mixes further with digestive enzymes from the pancreas, and then passes through the small intestine, where digestion continues. When the chyme is fully digested, it is absorbed into the blood. 95% of absorption of nutrients occurs

neg: Extracellular digestion system because every cell is exposed to all stages of food digestion. Specializing occurs when the digestive tract or alimentary canal has a separate mouth and anus so that transport of food is one-way. The most primitive digestive tract is seen in nematodes (phylum Nematode), where it is simply a tubular gut lined by an epithelial membrane. Earthworms (phylum Annelids) have a digestive tract specialized in different regions for the ingestion, storage, fragmentation, digestion and absorption of food. All more complex animal groups, including all vertebrates, show similar specializations. The ingested food may be stored in a specialized region of

neg: Digestion Digestion Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. In chemical digestion, enzymes break down food into the

neg: Human digestive system starts to work on breaking down fats. Lipase is further produced in the pancreas where it is released to continue this digestion of fats. The presence of salivary lipase is of prime importance in young babies whose pancreatic lipase has yet to be developed. As well as its role in supplying digestive enzymes, saliva has a cleansing action for the teeth and mouth. It also has an immunological role in supplying antibodies to the system, such as immunoglobulin A. This is seen to be key in preventing infections of the salivary glands, importantly that of parotitis. Saliva also contains a

neg: Intracellular digestion digested by the lysosome's enzymes. Intracellular digestion can also refer to the process in which animals that "lack" a digestive tract bring food items into the cell for the purposes of digestion for nutritional needs. This kind of intracellular digestion occurs in many unicellular protozoans, in Pycnogonida, in some molluscs, Cnidaria and Porifera. There is another type of digestion, called extracellular digestion. In amphioxus, digestion is both extracellular and intracellular. Intracellular digestion is divided into heterophagic digestion and autophagic digestion. These two types take place in the lysosome and they both have very specific functions. Heterophagic intracellular digestion has an

neg: Healthy digestion Healthy digestion Healthy digestion, also called digestive health, results in the absorption of nutrients from food without distressing symptoms. Healthy digestion follows having a healthy diet, doing appropriate self-care including physical activity and exercise, minimizing activities like smoking or consuming alcoholic drinks which impair digestion, and managing any medical condition which disrupts digestion to the best of one's ability. A person with healthy digestion will have lower risk of experiencing diarrhea, constipation, heartburn, bloating, flatulence, and indigestion. Additionally, a person with healthy digestion will have less need of digestive medications than a person who does not have healthy digestion. Some

neg: Human digestive system role in the body's metabolism. The liver has many functions some of which are important to digestion. The liver can detoxify various metabolites; synthesise proteins and produce biochemicals needed for digestion. It regulates the storage of glycogen which it can form from glucose (glycogenesis). The liver can also synthesise glucose from certain amino acids. Its digestive functions are largely involved with the breaking down of carbohydrates. It also maintains protein metabolism in its synthesis and degradation. In lipid metabolism it synthesises cholesterol. Fats are also produced in the process of lipogenesis. The liver synthesises the bulk of lipoproteins. The liver

neg: Proteolysis activation and interaction that result in an attack on invading pathogens. Protein degradation may take place intracellularly or extracellularly. In digestion of food, digestive enzymes may be released into the environment for extracellular digestion whereby proteolytic cleavage breaks down proteins into smaller peptides and amino acids so that they may be absorbed and used by an organism. In animals the food may be processed extracellularly in specialized digestive organs or guts, but in many bacteria the food may be internalized into the cell via phagocytosis. Microbial degradation of protein in the environment can be regulated by nutrient availability. For example,

neg: Crocodilia divided into two parts: a muscular gizzard that grinds food, and a digestive chamber where enzymes work on it. The stomach is more acidic than that of any other vertebrate and contains ridges for gastroliths, which play a role in the mechanical breakdown of food. Digestion takes place more quickly at higher temperatures. Crocodilians have a very low metabolic rate and consequently, low energy requirements. This allows them to survive for many months on a single large meal, digesting the food slowly. They can withstand extended fasting, living on stored fat between meals. Even recently hatched crocodiles are able to

neg: Snake dormant while the process of digestion takes place. Digestion is an intense activity, especially after consumption of large prey. In species that feed only sporadically, the entire intestine enters a reduced state between meals to conserve energy. The digestive system is then 'up-regulated' to full capacity within 48 hours of prey consumption. Being ectothermic ("cold-blooded"), the surrounding temperature plays a large role in snake digestion. The ideal temperature for snakes to digest is . So much metabolic energy is involved in a snake's digestion that in the Mexican rattlesnake ("Crotalus durissus"), surface body temperature increases by as much as during

neg: Human digestive system the esophagus at its upper end and to the duodenum at its lower end. Gastric acid (informally "gastric juice"), produced in the stomach plays a vital role in the digestive process, and mainly contains hydrochloric acid and sodium chloride. A peptide hormone, gastrin, produced by G cells in the gastric glands, stimulates the production of gastric juice which activates the digestive enzymes. Pepsinogen is a precursor enzyme (zymogen) produced by the gastric chief cells, and gastric acid activates this to the enzyme pepsin which begins the digestion of proteins. As these two chemicals would damage the stomach wall, mucus is

neg: Human digestive system are "spent". This is why it is sometimes known as the 'graveyard of red blood cells'. A product of this "digestion" is the pigment bilirubin, which is sent to the liver and secreted in the bile. Another product is iron, which is used in the formation of new blood cells in the bone marrow. Medicine treats the spleen solely as belonging to the lymphatic system, though it is acknowledged that the full range of its important functions is not yet understood. The liver is the second largest organ (after the skin) and is an accessory digestive gland which plays a

neg: Human digestive system In the duodenum, pancreatic lipase is secreted together with a co-enzyme, colipase to further digest the fat content of the chyme. From this breakdown, smaller particles of emulsified fats called chylomicrons are produced. There are also digestive cells called enterocytes lining the intestines (the majority being in the small intestine). They are unusual cells in that they have villi on their surface which in turn have innumerable microvilli on their surface. All these villi make for a greater surface area, not only for the absorption of chyme but also for its further digestion by large numbers of digestive enzymes present

neg: Digestion intestine. Water and minerals are reabsorbed back into the blood in the colon (large intestine) where the pH is slightly acidic about 5.6 ~ 6.9. Some vitamins, such as biotin and vitamin K (KMK7) produced by bacteria in the colon are also absorbed into the blood in the colon. Waste material is eliminated from the rectum during defecation. Digestive systems take many forms. There is a fundamental distinction between internal and external digestion. External digestion developed earlier in evolutionary history, and most fungi still rely on it. In this process, enzymes are secreted into the environment surrounding the organism, where

neg: Power Reactor and Nuclear Fuel Development Corporation harmful plutonium is to a human depends on the chemical form of the plutonium and the mode of exposure. Powdered plutonium dioxide (the form in MOX) is very resistant to digestion in acid, if swallowed it is likely to pass through the digestive system and leave in the stool. However, when inhaled, finely powdered plutonium dioxide will stay in the lungs for a long time thus exposing the person to a far higher radiation dose for a given amount of plutonium radioactivity. Water-soluble forms of plutonium can be absorbed in the digestive system, work done in the 1970s suggests that

neg: Nuruk necessary for normal digestive function and protect the flora of gut from harmful organisms. Fermented foods also have been broken down or “pre-digested" and therefore, unlike ordinary carbohydrates, place a lighter burden on the digestion system. They have many additional benefits (Helmenstine 25-28). Fermented food and drink such as Shindari are said to improve the immune system, prevent cancer, and increase beneficial bacteria in the digestive system, balancing the production of stomach acid and aiding nutrient absorption. Traditional fermented food helps the body to produce acetylcholine. It is especially beneficial for people with diabetes. Nuruk Nuruk () is a traditional

neg: Human digestive system The duodenum is the first and shortest section of the small intestine. It is a hollow, jointed C-shaped tube connecting the stomach to the jejunum. It starts at the duodenal bulb and ends at the suspensory muscle of duodenum. The attachment of the suspensory muscle to the diaphragm is thought to help the passage of food by making a wider angle at its attachment. Most food digestion takes place in the small intestine. Segmentation contractions act to mix and move the chyme more slowly in the small intestine allowing more time for absorption (and these continue in the large intestine).

neg: Fetal pig pass directly from the right to left atrium. There is also the ductus arterius which allows blood from the right atrium to be diverted to the aortic arch. Both of these shunts close a few minutes after birth. The monogastric digestive system of the fetal pig harbors many similarities with many other mammals. The fetal pig's digestive organs are well developed before birth, although it does not ingest food. These organs include the esophagus, stomach, small and large intestines. Mesenteries serve to connect the organs of the fetal pig together. In order for digestion to occur, the fetal pig would

neg: Casomorphin Casomorphin Casomorphin is an opioid peptide (protein fragment) derived from the digestion of the milk protein casein. Digestive enzymes can break casein down into peptides that have some biological activity in cells and in laboratory animals though conclusive causal effects on humans have not been established. Although they have not yet been proven to be formed in the human digestive system, there are associations between serum levels of β-casomorphins and the risk of sudden infant death syndrome, histamine release, stimulation of food intake, specifically high-fat foods, and lymphocytosis. Although research has shown high rates of use of complementary and alternative

neg: Human digestive system doesn't empty properly the systems can fail. This is how gallstones form when a small piece of calcium gets coated with either cholesterol or bilirubin and the bile crystallises and forms a gallstone. The main purpose of the gallbladder is to store and release bile, or "gall". Bile is released into the small intestine in order to help in the digestion of fats by breaking down larger molecules into smaller ones. After the fat is absorbed, the bile is also absorbed and transported back to the liver for reuse. The pancreas is a major organ functioning as an accessory digestive

neg: Stomach Stomach The stomach (from ancient Greek στόμαχος, "stomachos," "stoma" means mouth) is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital digestive organ. In the digestive system the stomach is involved in the second phase of digestion, following mastication (chewing). In humans and many other animals, the stomach is located between the oesophagus and the small intestine. It secretes digestive enzymes and gastric acid to aid in food digestion. The pyloric sphincter controls the passage of partially digested food (chyme) from

neg: Bicarbonate bicarbonate – in conjunction with water, hydrogen ions, and carbon dioxide – forms this buffering system, which is maintained at the volatile equilibrium required to provide prompt resistance to pH changes in both the acidic and basic directions. This is especially important for protecting tissues of the central nervous system, where pH changes too far outside of the normal range in either direction could prove disastrous (see acidosis or alkalosis). Bicarbonate also serves much in the digestive system. It raises the internal pH of the stomach, after highly acidic digestive juices have finished in their digestion of food. Bicarbonate also

neg: Human digestive system the stomach. It connects to the duodenum via the pancreatic duct which it joins near to the bile duct's connection where both the bile and pancreatic juice can act on the chyme that is released from the stomach into the duodenum. Aqueous pancreatic secretions from pancreatic duct cells contain bicarbonate ions which are alkaline and help with the bile to neutralise the acidic chyme that is churned out by the stomach. The pancreas is also the main source of enzymes for the digestion of fats and proteins. Some of these are released in response to the production of CKK in

neg: Sham feeding absorbed into the body, the process of chewing still stimulates digestive system nerves which trigger the release of gastrointestinal hormones, and also increase the production of both saliva and pancreatic secretions. In human studies a process known as modified sham feeding (MSF) is typically used, which involves smelling, tasting and chewing food, then spitting it out when it would normally be swallowed. Sham feeding Sham feeding is any procedure that mimics normal food consumption but where food and drink are not actually digested or absorbed. It is generally used in experiments studying hunger, eating or digestion, and is a predominant

neg: Even-toed ungulate cellulose found in plant material. This form of digestion has two advantages: plants that are indigestible to other species can be digested and used, and the duration of the actual food consumption shortened; the animal spends only a short time out in the open with his head to the ground – rumination can take place later, in a sheltered area. Tylopoda (camels, llamas, and alpacas) and chevrotains have three-chambered stomachs, while the rest of Ruminantia have four-chambered stomachs. The handicap of a heavy digestive system has increased selective pressure towards limbs that allow the animal to quickly escape predators. Most

neg: Lethal white syndrome system where most digestion takes place, and comprises the cecum, the colon, and the rectum. Necropsies on LWS foals reveal a pale, underdeveloped colon and intestinal obstruction (impaction). Samples of affected tissue show a lack of nerves that allow the intestine to move material through the digestive system, a condition called intestinal agangliosis. Closer examination of the skin and hair shows both to be unpigmented, and most hair follicles are inactive and many are devoid of hair altogether. All LWS foals test homozygous for a genetic abnormality. Genetic conditions which affect more than one physical trait—in the case of lethal

neg: Human digestive system its nutrients the remaining waste material changes into the semi-solids called feces, which pass to the large intestine, where bacteria in the gut flora further break down residual proteins and starches. The cecum is a pouch marking the division between the small intestine and the large intestine. The cecum receives chyme from the last part of the small intestine, the ileum, and connects to the ascending colon of the large intestine. At this junction there is a sphincter or valve, the ileocecal valve which slows the passage of chyme from the ileum, allowing further digestion. It is also the site

neg: Digestive enzyme a major role in digestion, both in a mechanical sense by mixing and crushing the food, and also in an enzymatic sense, by digesting it. The following are enzymes produced by the stomach and their respective function: Hormones or compounds produced by the stomach and their respective function: Of note is the division of function between the cells covering the stomach. There are four types of cells in the stomach: Secretion by the previous cells is controlled by the enteric nervous system. Distention in the stomach or innervation by the vagus nerve (via the parasympathetic division of the autonomic nervous

neg: Beetle any appendages, but some (for example, Mordellidae) have articulating sternal lobes. The digestive system of beetles is primarily adapted for a herbivorous diet. Digestion takes place mostly in the anterior midgut, although in predatory groups like the Carabidae, most digestion occurs in the crop by means of midgut enzymes. In the Elateridae, the larvae are liquid feeders that extraorally digest their food by secreting enzymes. The alimentary canal basically consists of a short, narrow pharynx, a widened expansion, the crop, and a poorly developed gizzard. This is followed by the midgut, that varies in dimensions between species, with a large

neg: Ruminant Ruminant Ruminants are mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The process, which takes place in the front part of the digestive system and therefore is called foregut fermentation, typically requires the fermented ingesta (known as cud) to be regurgitated and chewed again. The process of rechewing the cud to further break down plant matter and stimulate digestion is called rumination. The word "ruminant" comes from the Latin "ruminare", which means "to chew over again". The roughly 200 species of living ruminants include

neg: Mechanical biological treatment advantageous for later transport and combustion. Some systems incorporate both anaerobic digestion and composting. This may either take the form of a full anaerobic digestion phase, followed by the maturation (composting) of the digestate. Alternatively a partial anaerobic digestion phase can be induced on water that is percolated through the raw waste, dissolving the readily available sugars, with the remaining material being sent to a windrow composting facility. By processing the biodegradable waste either by anaerobic digestion or by composting MBT technologies help to reduce the contribution of greenhouse gases to global warming. Usable wastes for this system: Possible products

neg: Human waste Human waste Human waste (or human excreta) refers to the waste products of the human digestive system and the human metabolism, namely feces and urine. As part of a sanitation system that is in place, human waste is collected, transported, treated and disposed of or reused by one method or another, depending on the type of toilet being used, ability by the users to pay for services and other factors. The sanitation systems in place differ vastly across the world, with many people in developing countries having to resort to open defecation where human waste is deposited in the environment,

neg: Lipase Lipase A lipase (, ) is any enzyme that catalyzes the hydrolysis of fats (lipids). Lipases are a subclass of the esterases. Lipases perform essential roles in digestion, transport and processing of dietary lipids (e.g. triglycerides, fats, oils) in most, if not all, living organisms. Genes encoding lipases are even present in certain viruses. Most lipases act at a specific position on the glycerol backbone of a lipid substrate (A1, A2 or A3)(small intestine). For example, human pancreatic lipase (HPL), which is the main enzyme that breaks down dietary fats in the human digestive system, converts triglyceride substrates found in

neg: Gastrointestinal tract small intestine, and large intestine. However, the complete human digestive system is made up of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver and gallbladder). The tract may also be divided into foregut, midgut, and hindgut, reflecting the embryological origin of each segment. The whole human GI tract is about nine metres (30 feet) long at autopsy. It is considerably shorter in the living body because the intestines, which are tubes of smooth muscle tissue, maintain constant muscle tone in a halfway-tense state but can relax in spots to allow for local distention

neg: Insect simple sugars before being used by cells of the body for energy, growth, or reproduction. This break-down process is known as digestion. It should be emphasized that there is extensive variation among different orders, life stages, and even castes in the digestive system of insects . This is the result of extreme adaptations to various lifestyles. The present description focus on a generalized composition of the digestive system of an adult orthopteroid insect, which is considered basal to interpreting particularities of other groups. The main structure of an insect's digestive system is a long enclosed tube called the alimentary canal,

neg: Healthy digestion them after they begin. Various drugs can relieve the symptoms of poor digestion. Laxatives counter constipation. Loperamide counters diarrhea. An antacid can counter heartburn or indigestion. Simethicone can counter flatulence. Probiotic treatment to promote healthy digestion is popular. Many people who seek healthcare for gastrointestinal problems are not satisfied with the treatment options which they find in conventional medicine. Because of this, people often use alternative medicine to promote healthy digestion. Various organizations observe a "World Digestive Health Day" to share information about promoting healthy digestion. Healthy digestion Healthy digestion, also called digestive health, results in the absorption of nutrients

neg: Mammal to bacteria that ferment these complex substances, and make them available for digestion, which are either housed in the multichambered [[stomach]] or in a large cecum. Some mammals are [[coprophagous]], consuming [[feces]] to absorb the nutrients not digested when the food was first ingested. An [[omnivore]] eats both prey and plants. Carnivorous mammals have a simple [[digestive system|digestive tract]] because the [[protein]]s, [[lipid]]s and [[mineral]]s found in meat require little in the way of specialized digestion. Exceptions to this include [[baleen whale]]s who also house [[gut flora]] in a multi-chambered stomach, like terrestrial herbivores. The size of an animal is

neg: Mechanical biological treatment and has a lower impact than either MBT processes producing RDF for incineration or incineration of waste without MBT. Friends of the Earth does not support MBT plants that produce refuse derived fuel (RDF), and believes MBT processes should occur in small, localised treatment plants. Mechanical biological treatment A mechanical biological treatment system is a type of waste processing facility that combines a sorting facility with a form of biological treatment such as composting or anaerobic digestion. MBT plants are designed to process mixed household waste as well as commercial and industrial wastes. The terms "mechanical biological treatment" or "mechanical

neg: Italian crested newt the creation of new cells and building of new tissue. In short, where the damage occurs is directly related to how much regeneration will occur. There are broad generalizations relating to amphibians that can be used to describe their digestive processes. One such generalization is that digestion raises metabolic rate in the organism in which it is occurring. This wide idea will apply to "T. carnifex". Digestion results in a hypertrophy (swelling) of the gastrointestinal regions. This is similar to the shunting of blood flow to the gastrointestinal compartments, as seen in muscular exercise. Both activities place a specific demand

neg: Creatorrhea therefore released in the feces. Trypsinogen is produced in the pancreas and released into the alimentary canal where it is converted to the active enzyme trypsin. Inflammation of the pancreas, or pancreatitis can therefore precipitate this condition, as can cystic fibrosis which also affects the production of digestive enzymes. Creatorrhea Creatorrhea is the abnormal excretion of muscle fibre in feces. The term is made from the prefix "creat-" or "creato-" which comes from Greek "kreas" meaning "flesh". The suffix "-rrhea" (or "-rrhoea") comes from Greek "-rrhoia" meaning "flow," hence discharge. Digestion of food is achieved through a mixture of mechanical

neg: Fish physiology the intestine. These animals all consume diets that either require little storage of food, or no pre-digestion with gastric juices, or both. The small intestine is the part of the digestive tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In fish, the divisions of the small intestine are not clear, and the terms "anterior" or "proximal" intestine may be used instead of duodenum. The small intestine is found in all teleosts, although its form and length vary enormously between species. In teleosts, it is relatively

neg: Creatorrhea Creatorrhea Creatorrhea is the abnormal excretion of muscle fibre in feces. The term is made from the prefix "creat-" or "creato-" which comes from Greek "kreas" meaning "flesh". The suffix "-rrhea" (or "-rrhoea") comes from Greek "-rrhoia" meaning "flow," hence discharge. Digestion of food is achieved through a mixture of mechanical and chemical processes. Failure to produce or secrete chemicals known as digestive enzymes can lead to failure digesting or breaking down specific components of ingested food. Where there is a failure to produce, release, or convert trypsinogen—an inactive enzyme precursor or zymogen—muscle fibres are not properly digested and are

neg: Human nutrition subcategories are insoluble and soluble fiber. Insoluble dietary fiber consists mainly of cellulose, a large carbohydrate polymer that is indigestible by humans, because humans do not have the required enzymes to break it down, and the human digestive system does not harbor enough of the types of microbes that can do so. Soluble dietary fiber comprises a variety of oligosaccharides, waxes, esters, resistant starches, and other carbohydrates that dissolve or gelatinize in water. Many of these soluble fibers can be fermented or partially fermented by microbes in the human digestive system to produce short-chain fatty acids which are absorbed and

neg: Human digestive system layer of the body is of smooth muscle tissue that helps the gallbladder contract, so that it can discharge its bile into the bile duct. The gallbladder needs to store bile in a natural, semi-liquid form at all times. Hydrogen ions secreted from the inner lining of the gallbladder keep the bile acidic enough to prevent hardening. To dilute the bile, water and electrolytes from the digestion system are added. Also, salts attach themselves to cholesterol molecules in the bile to keep them from crystallising. If there is too much cholesterol or bilirubin in the bile, or if the gallbladder

neg: Control of fire by early humans other primates. Due to the increased digestibility cooked foods conferred, less digestion was needed to procure the necessary nutrients. As a result, the gastrointestinal tract and organs in the digestive system decreased in size. This is in contrast to other primates, where a larger digestive tract is needed for fermentation of long carbohydrate chains. Thus, humans evolved from the large colons and tracts that are seen in other primates to smaller ones. According to Wrangham, control of fire allowed hominids to sleep on the ground and in caves instead of trees and led to more time being spent on the

neg: Human waste (sewage) is used to irrigate and fertilize fields in many parts of the developing world where fresh water is unavailable. There is great potential for wastewater agriculture to produce more food for consumers in urban areas, as long as there is sufficient education about the dangers of eating such food uncooked. Human waste Human waste (or human excreta) refers to the waste products of the human digestive system and the human metabolism, namely feces and urine. As part of a sanitation system that is in place, human waste is collected, transported, treated and disposed of or reused by one method

neg: Edward Stevens (diplomat) Stevens' dissertation on gastric digestion was entitled "De alimentorum concoctione". Based on this work, he was the first researcher to isolate human gastric juices. His work confirmed that of René Antoine Ferchault de Réaumur, who showed the digestive power of gastric juices, and helped dispel earlier theories of digestion. Stevens's work on digestion would influence Lazzaro Spallanzani. On January 20, 1776, Stevens was admitted to the university's Royal Medical Society. He served as the Society's president for the academic year 1779/1780. Stevens conducted experimental inquiry into the color of blood and received a prize for his work. Stevens remained in

neg: Syntrophy human body, for example throughout the alimentary canal and on the skin, is in the region of 10 times the total number of human cells in it. These microbes are vital, for instance for the digestive and the immune system to function. Another example is the many organisms that feed on faeces or dung. A cow diet consists mainly of grass, the cellulose of which is transformed into lipids by micro-organisms in the cow's large intestine. These micro-organisms cannot use the lipids because of lack of oxygen in the intestine, so the cow does not take up all lipids produced.

neg: Dual inheritance theory a Scandinavian population the estimated selection coefficient was 0.09-0.19. This implies that the cultural practice of raising cattle first for meat and later for milk led to selection for genetic traits for lactose digestion. Recently, analysis of natural selection on the human genome suggests that civilization has accelerated genetic change in humans over the past 10,000 years. Food processing Culture has driven changes to the human digestive systems making many digestive organs, like our teeth or stomach, smaller than expected for primates of a similar size, and has been attributed to one of the reasons why humans have such large

neg: Equine nutrition "haylage" is fed to horses in some places; however, contamination or failure of the fermentation process that allows any mold or spoilage may be toxic. Horses and other members of the genus "Equus" are adapted by evolutionary biology to eating small amounts of the same kind of food all day long. In the wild, horses ate prairie grasses in semi-arid regions and traveled significant distances each day in order to obtain adequate nutrition. Therefore, their digestive system was made to work best with a small but steady flow of food that does not change much from day to day. Digestion

neg: Digestion that move along the stomach wall. This allows the mass of food to further mix with the digestive enzymes. After some time (typically 1–2 hours in humans, 4–6 hours in dogs, 3–4 hours in house cats), the resulting thick liquid is called chyme. When the pyloric sphincter valve opens, chyme enters the duodenum where it mixes with digestive enzymes from the pancreas and bile juice from the liver and then passes through the small intestine, in which digestion continues. When the chyme is fully digested, it is absorbed into the blood. 95% of absorption of nutrients occurs in the small

neg: Gastrointestinal tract the stomach, distal duodenum, ascending colon, descending colon and anal canal. In addition, the oral cavity has adventitia. Approximately 20,000 protein coding genes are expressed in human cells and 75% of these genes are expressed in at least one of the different parts of the digestive organ system. Over 600 of these genes are more specifically expressed in one or more parts of the GI tract and the corresponding proteins have functions related to digestion of food and uptake of nutrients. Examples of specific proteins with such functions are pepsinogen PGC and the lipase LIPF, expressed in chief cells, and

neg: Pepsin in its active site. It is one of three principal proteases in the human digestive system, the other two being chymotrypsin and trypsin. During the process of digestion, these enzymes, each of which is specialized in severing links between particular types of amino acids, collaborate to break down dietary proteins into their components, i.e., peptides and amino acids, which can be readily absorbed by the small intestine. Pepsin is most efficient in cleaving peptide bonds between hydrophobic and preferably aromatic amino acids such as phenylalanine, tryptophan, and tyrosine. Pepsin's proenzyme, pepsinogen, is released by the chief cells in the stomach

neg: Infant nutrition reduce the incidence of SIDS. Breast milk is important for the infant’s digestive system. It is the best substance to give, especially over cow's milk. Infants cannot properly digest fats, which cow's milk is full of. Breast milk contains a lot of fat, too, but it also contains lipase, a substance to help break down fat to aid in digestion. This leads to infants passing softer stools, so constipation is rare in breastfed infants. Human milk also allows beneficial bacteria to grow in the infant’s intestines, which protects the mucosal barrier of the infant's stomach. This prevents harmful pathogens from

neg: Cnidaria gastroderm release enzymes that reduce the prey to slurry, usually within a few hours. This circulates through the digestive cavity and, in colonial cnidarians, through the connecting tunnels, so that gastroderm cells can absorb the nutrients. Absorption may take a few hours, and digestion within the cells may take a few days. The circulation of nutrients is driven by water currents produced by cilia in the gastroderm or by muscular movements or both, so that nutrients reach all parts of the digestive cavity. Nutrients reach the outer cell layer by diffusion or, for animals or zooids such as medusae which

neg: Human digestive system is located in the upper right quadrant of the abdomen and below the diaphragm to which it is attached at one part, This is to the right of the stomach and it overlies the gall bladder. The liver produces bile, an important alkaline compound which aids digestion. Bile produced by the liver is made up of water (97%), bile salts, mucus and pigments, 1% fats and inorganic salts. Bilirubin is its major pigment. Bile acts partly as a surfactant which lowers the surface tension between either two liquids or a solid and a liquid and helps to emulsify the fats

neg: Microbiology each microorganism to degrade toxic waste depends on the nature of each contaminant. Since sites typically have multiple pollutant types, the most effective approach to microbial biodegradation is to use a mixture of bacterial and fungal species and strains, each specific to the biodegradation of one or more types of contaminants. Symbiotic microbial communities confer benefits to their human and animal hosts health including aiding digestion, producing beneficial vitamins and amino acids, and suppressing pathogenic microbes. Some benefit may be conferred by eating fermented foods, probiotics (bacteria potentially beneficial to the digestive system) or prebiotics (substances consumed to promote the

neg: Human digestive system secreted by innumerable gastric glands in the stomach, to provide a slimy protective layer against the damaging effects of the chemicals on the inner layers of the stomach. At the same time that protein is being digested, mechanical churning occurs through the action of peristalsis, waves of muscular contractions that move along the stomach wall. This allows the mass of food to further mix with the digestive enzymes. Gastric lipase secreted by the chief cells in the fundic glands in the gastric mucosa of the stomach, is an acidic lipase, in contrast with the alkaline pancreatic lipase. This breaks down

neg: Imaging science developing a system for creating visual renderings (images). In general, the links of the imaging chain include: 1. The human visual system. Designers must also consider the psychophysical processes which take place in human beings as they make sense of information received through the visual system. 2. The subject of the image. When developing an imaging system, designers must consider the observables associated with the subjects which will be imaged. These observables generally take the form of emitted or reflected energy, such as electromagnetic energy or mechanical energy. 3. The capture device. Once the observables associated with the subject are

neg: Biotic stress on an insects digestive system. The plants do this using proteinase inhibitors. These proteinase inhibitors prevent protein digestion and once in the digestive system of an insect, they bind tightly and specifically to the active site of protein hydrolysing enzymes such as trypsin and chymotrypsin. This mechanism is most likely to have evolved in plants when dealing with insect attack. Plants detect elicitors in the insects saliva. Once detected, a signal transduction network is activated. The presence of an elicitor causes an influx of Ca ions to be released in to the cytosol. This increase in cytosolic concentration activates target

neg: Randy Lee Cutler "Open Wide: An Abecedarium for the Great Digestive System", an ebook on digestion as a metaphor for experience. The book mimics the digestive system, and its chronology is run by the alphabet. It features illustrations, media and sound by Abbas Akhavan, Myron Campbell, Gaye Chan, John Cussans, Geoffrey Farmer, Kristina Fiedrich, Monique Fouquet, Allison Hrabluik, Elvira Hufschmid, Ingrid Koenig, Germaine Koh, Elizabeth MacKenzie, Liz Magor, Graham Meisner, Cindy Mochizuki, Damian Moppett, Ranu Mukherjee, Ryan Peter, Marina Roy, Margit Schild, and Holly Schmidt. Randy Lee Cutler Randy Lee Cutler is a writer, academic, educator and artist working in Vancouver, British Columbia.

neg: Mexican howler to be a frugivore and a behavioural folivores. Their digestive system is slow and they have significantly fewer enzymes for protein and fiber digestion than other frugivores, but they compensate for this by selectively eating leaves with less fiber. Consequently, much of this the Mexican howler monkey's activity is dedicated for foraging for fruit and young leaves which it can easily digest. Frugivory is typically observed in New World monkeys instead of Old World monkeys, but howler monkeys are an exception to this categorization. This howler monkey species has compensated for its adapted digestive system by minimizing energy output as

neg: Human digestive system cavity where most of the digestive organs are located. The suspensory muscle attaches the ascending duodenum to the diaphragm. This muscle is thought to be of help in the digestive system in that its attachment offers a wider angle to the duodenojejunal flexure for the easier passage of digesting material. The diaphragm also attaches to, and anchors the liver at its bare area. The esophagus enters the abdomen through a hole in the diaphragm at the level of T10. The stomach is a major organ of the gastrointestinal tract and digestive system. It is a consistently J-shaped organ joined to

neg: Enterocyte Enterocyte Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells found in the small intestine. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase surface area for the digestion and transport of molecules from the intestinal lumen. The cells also have a secretory role. The major functions of enterocytes include: Dietary fructose intolerance occurs when there is a deficiency in the amount of fructose carrier. Lactose intolerance is the most common problem of carbohydrate digestion and occurs when the human body doesn't produce a sufficient amount of lactase (a disaccharidase) enzyme to break down the

neg: Digesting Duck Duck is featured in Lavie Tidhar's "The Bookman", in the Egyptian Hall, alongside the Turk. In 2006, Belgian conceptual artist Wim Delvoye introduced the world to his "Cloaca Machine", a mechanical art work that actually digests food and turns it into excrement, finally fulfilling Vaucanson's wish for a working digestive automation. Many iterations of the Cloaca Machine have since been produced; the current iteration sits vertically, mimicking the human digestive system. The excrement produced by the machine is vacuum-sealed in Cloaca-branded bags and sold to art collectors and dealers; every series of excrements produced has sold out. Digesting Duck The

neg: Gastric acid gastric acid, verifying that acid played a crucial role in digestion. Gastric acid Gastric acid, gastric juice or stomach acid, is a digestive fluid formed in the stomach and is composed of hydrochloric acid (HCl), potassium chloride (KCl) and sodium chloride (NaCl). The acid plays a key role in digestion of proteins, by activating digestive enzymes, and making ingested proteins unravel so that digestive enzymes break down the long chains of amino acids. Gastric acid is produced by cells in the lining of the stomach, which are coupled in feedback systems to increase acid production when needed. Other cells in

neg: Ruminant of lifecycle assessment studies. Methane production by meat animals, principally ruminants, is estimated 15–20% global production of methane, unless the animals were hunted in the wild. Ruminant Ruminants are mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The process, which takes place in the front part of the digestive system and therefore is called foregut fermentation, typically requires the fermented ingesta (known as cud) to be regurgitated and chewed again. The process of rechewing the cud to further break down plant matter and stimulate

neg: Serine protease "trypsin" is essential, because it activates its own reaction, as well as the reaction of both "chymotrypsin" and "elastase". Therefore, it is essential that this activation does not occur prematurely. There are several protective measures taken by the organism to prevent self-digestion: There are certain inhibitors that resemble the tetrahedral intermediate, and thus fill up the active site, preventing the enzyme from working properly. Trypsin, a powerful digestive enzyme, is generated in the pancreas. Inhibitors prevent self-digestion of the pancreas itself. Serine proteases are paired with serine protease inhibitors, which turn off their activity when they are no longer needed.

neg: The Description of the Human Body soul. A sick or injured body does not do what we want or moves in ways we do not want. He believed the death of the body stopped it from being fit to bring about movement. This did not necessarily happen because the soul left the body. René Descartes believed the body could exist through mechanical means alone. This included digestion, blood circulation, muscle movement and some brain function. He felt we all know what the human body is like because animals have similar bodies and we have all seen them opened up. He saw the body as a machine.

neg: Orchid mycorrhiza digestion are a continuum and will cyclically occur throughout the entire life span of the cooperation. Rasmussen 2009 differentiates two types of plant host cells which are involved in nutrient transfer, so called 'digestion cells' and so called 'host cells', 'digestive cells' apparently engage in dense hyphal peloton formation followed by a rapid digestion and subsequent reinfection, where as 'host cells' contain live hyphae pelotons, which will not be digested, or at least not as readily. Rasmussen 2002 discusses an additional mode of nutrient transfer called pytophagy involving lysis of fungal cells but instead of lysing the entire fungal hyphae

neg: Stomach the small intestine, where the extraction of nutrients begins. Depending on the quantity and contents of the meal, the stomach will digest the food into chyme within anywhere between forty minutes and a few hours. The average human stomach can comfortably hold about a litre of food. Gastric juice in the stomach also contains pepsinogen. Hydrochloric acid activates this inactive form of enzyme into the active form, pepsin. Pepsin breaks down proteins into polypeptides. Although the absorption in the human digestive system is mainly a function of the small intestine, some absorption of certain small molecules nevertheless does occur in