The alimentary system

Ursodeoxycholic acid (ursodiol), which is found in large quantities in bear bile, and which elicits an intense bitter taste, has long been used in traditional Chinese medicine not only as a stomachic but also as a universal drug for the alimentary system.1 8 Currently, the drug is generally derived by chemical synthesis rather than from animals. 

Paracelsus made the general introduction of several heavy metals into medicine in the 16th century and nowadays the particular use of bismuth compounds is focused upon the treatment of disorders of the alimentary system (14 such drugs are commonly prescribed in Britain). Several of these medicines are based upon a red viscous colloidal bismuth citrate solution containing ammonium hydroxide plus a colourant, a sweetening agent and emollients such as sorbitol or glycerine at pH = 10. 

The parasitic phase is initiated by ingested conidia lodging on the wall of the alimentary system between the mouth and the mastax. Rotiferophthora species are among the most frequently recorded parasites of bdelloid rotifers. They are devastating parasites, able to wipe out entire populations of rotifers in Petri dishes in a few days (Barron, 1991a, 1991b). 

Drugs administered to the intestine as the lower end of the alimentary system are expected to reach the entire body. Because drugs absorbed from the distal portion of the intestine can avoid the initial passage effect, it is necessary to attempt to control migration of the dmg to the upper part of the intestine. For example, a double-layered suppository that has an ammonium salt of carboxyvinyl polymer at the front tip could be used. 

Toxic actions on the alimentary system may be as a direct action on the stmctures of the system itself or as a route for absorption of a toxic agent into the body. The alimentary system is perhaps the most familiar form and route of the production of toxic trauma. 

Picomaviruses Poliovirus Naked icosahedral particles 28 nm in diameter One of a group of enteroviruses common in the gut of humans. The primary site of multiplication is the lymphoid tissue of the alimentary tract. Only rarely do they cause systemic infections or serious neurological conditions like encephalitis or poliomyelitis... 

Many drugs are administered as parenterals for speed of action because the patient is unable to take oral medication or because the drug is a macromolecule such as a protein that is unable to be orally absorbed intact due to stability and permeability issues. The U.S. Pharmacopoeia defines parenteral articles as preparations intended for injection through the skin or other external boundary tissue, rather than through the alimentary canal. They include intravenous, intramuscular, or subcutaneous injections. Intravenous injections are classified as small volume (<100 mL per container) or large volume (>100 mL per container) injections. The majority of parenteral dosage forms are supplied as ready-to-use solutions or reconstituted into solutions prior to administration. Suspension formulations may also be used,101 although their use is more limited to a subcutaneous (i.e., Novolin Penfill NOVO Nordisk) or intramuscular (i.e., Sandostatin LAR Depot Novartis) injection. Intravenous use of disperse systems is possible but limited (i.e., Doxil Injection Ortho Biotec). 

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

Drugs are administered to animals by parenteral or enteral administration, and topical application. Parenteral administration bypasses the alimentary tract and can be effected by a variety of routes including intravenous, intramuscular, subcutaneous, intraperitoneal, or intrapleural injections inhalation and percuta-neously. In intravenous injections, entry of dmgs into the system depends only upon the rate of injection and not on absorption into the bloodstream. As a result, water-soluble poorly absorbed drugs may be readily administered. 

The Annelida (segmented worms)131 are believed to be evolutionary antecedents of the arthropods. Present-day members include earthworms, leeches, and -105 species of marine polychaetes. Annelids have a true body cavity separate from the alimentary canal and lined by a peritoneum. They have a well-developed circulatory system and their blood usually contains a type of hemoglobin. 

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