Digestion, alimentary

A brilliant success of modern biochemistry has been to show that all or almost all proteins of bovine pancreatic juice are enzymes (1). It may be said in a cursory way that this juice is a solution of enzymes in bicarbonate and that its composition is strictly utilitarian. Bicarbonate is present in order to neutralize hydrochloric acid coming from the stomach and to keep enzymes in solution. Enzymes are present for digesting alimentary products in the intestine. On the other hand, pancreatic juice seems to have been created for the protein chemist s delight, since its proteins are biologically active, relatively simple, and endowed with unusual properties. 

The first consideration was the speciation and distribution of the metal in the sediment and water. Benthic organisms are exposed to surface water, pore water and sediment via the epidermis and/or the alimentary tract. Common binding sites for the metals in the sediment are iron and manganese oxides, clays, silica often with a coating of organic carbon that usually accounts for ca. 2% w/w. In a reducing environment contaminant metals will be precipitated as their sulfides. There is not necessarily a direct relationship between bioavailability and bioaccumulation, as digestion affects the availability and transport of the metals in animals, in ways that differ from those in plants. 

A Alimentary tract and metabolism 520-579 240-279 Diseases of the digestive system Endocrine, nutritional, and metaholic diseases... 

Flatworms with an alimentary tract ingest food into this canal, where it is first digested and then absorbed by the intestinal epithelium. Ectoparasitic flatworms like monogenea are restricted to this type of food uptake. 

Metabolism of pectin. Pectin has only recently come, to be considered a part of the dietary fiber complex. Previously it was excluded because 1) it is not fibrous (except at the molecular level), 2) it escapes detection in standard fiber tests owing to its solubility, and 3) it usually does not survive intestinal passage. In a reassessment of which dietary components should be considered fiber, Trowell (49) proposed that dietary fiber include those constituents of food resistant to hydrolysis by man s alimentary enzymes. Spiller (50, 51) suggested that confusion surrounding the term "fiber" be avoided by using the term "plantix" to denote those plant materials of polymeric nature not attacked by human digestive enzymes. 

Stomach. The stomach is the first digestive organ that a drug encounters in the alimentary canal. The human stomach can be divided anatomically into (1) the cardia, the gastroesophageal sphincter, (2) the fundus, the uppermost part of stomach, (3) the body, a reservoir for food and fluids, and (4) the antrum, the lower part of the stomach. The diameter of the stomach in the fed state is quite variable depending on the area. The antrum diameter does not change much in the fed state, whereas the diameter of the body may increase several-fold. 

Kilpatrick, D. C., Pusztai, A., Grant, G., et al. Tomato lectin resists digestion in the mammalian alimentary canal and binds to intestinal villi without deleterious effects. 

Lobel, P.S., Trophic biology of herbivorous reef fish alimentary pH and digestive capabilities,./. Fish. Biol., 19, 365, 1981. 

Modify microecological conditions in the alimentary tract by modifying mutual quantitative ratios between the harmful microflora and the microorganisms which produce a beneficial effect on the digestive tract (Gibson 1998)... 

Very little appears to be known regarding the factors which determine the host specificity of coracidia in copepods. Clearly, the chief factors which may affect development are likely to be the nature of the digestive juices, the structure of the alimentary canal (especially its cellular thickness ) and the nature of the haemocoele, including the reactions of phagocytic or encapsulating cells. 

The eyes, mouth, nose, vagina and rectum have mucous membranes. These are sheets of epithelial (lining) cells that are moist owing to the production of a slimy secretion called mucus. Additionally, they line the alimentary (digestive) tract, respiratory tract and genito-urinary tracts. The mucus has a protective role to prevent injury to underlying tissues and traps foreign particles in the respiratory system. 

The physiological action of the cinchona alkaloids is that of an antipyretic or febrifugCj lowering the body temperature in case of fevers. Quinine retards the action of oxidase enzymes and acts as a poison to certain organisms, especially that of malaria. Its first use was as a specific for this form of fever. It has a very bitter taste and in common with other substances of like properties it acts on the alimentary canal causing increased secretion of digestive juices. 

Source of energy. Alcohol may be useful as an energy source (rather than a food) in debilitated patients. It is rapidly absorbed from the alimentary tract without requiring digestion and it supplies 7 calories per gram as compared with 9 from fat and 4 from carbohydrate and protein. Heavy doses cause hyperlipidaemia in some people. 

Oral administration is the most common route of drug administration. Major physiologic processes in the GI system include secretion, digestion, and absorption. Secretion includes the transport of fluid, electrolytes, peptides, and proteins into the lumen of the alimentary canal. Enzymes in saliva and pancreatic secretions are involved in the digestion of carbohydrates and proteins. Other secretions such as mucus protect the linings of the lumen of the GI tract. Digestion is the breakdown of food constituents into smaller structures in preparation for absorption. Both drug and food constituents are mostly absorbed in the proximal area (duodenum) of the small intestinal. The process of absorption is the entry of constituents from the lumen of the gut into the body. Absorption may be considered as the net result of both lumen-to-blood and blood-to-lumen transport movements. 

For the same reason it is difficult to prepare vaccines against them. Other flagellates live in a symbiotic relationship within the alimentary canals of termites (Fig. 1-9) and roaches. Termites depend upon bacteria that live within the cells of these symbiotic protozoans to provide the essential enzymes needed to digest the cellulose in wood. 

The gastrointestinal (GI) system consists of alimentary canal (digestive tract) ... 

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