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Cestoda
{{Taxobox
| color = pink
| name = Cestoda
| image = Tenia_solium_scolex.jpg
| image_width = 200px
| image_caption = Scolex of Tenia solium
| regnum = Animalia
| phylum = Platyhelminthes
| classis = Cestoda
| subdivision_ranks = Orders
| subdivision =
Subclass Cestodaria In biology, Cestoda is the classof parasiticflatworms, called tapeworms, that live in the digestive tractsof vertebratesas adults and often in the bodies of various animals as juveniles. In a tapeworm infection, adults absorb food predigested by the host, so the worms have no need for a digestive tractor a mouth. Large tapeworms are made almost entirely of reproductive structures with a small "head" for attachment. Symptoms vary widely, depending on the species causing the infection. Symptoms may include upper abdominal discomfort, diarrhea, and loss of appetite. However, infestations are usually asymptomatic. Worm segments or eggs may be found in the stool of an infected person. The largest tapeworms can be 80 feet or longer. Tapeworms harm their host by stealing vital nutrients, causing malnutrition and if left untreated can cause intestinal blockages. There are two subclassesin class Cestoda, the Cestodaria and the Eucestoda. By far the most common and widespread are the Eucestoda, with only a few species of unusual worms in subclass Cestodaria. The cyclophyllideansare of the most importance to humans because they infect people and livestock. Two important tapeworms are the pork tapeworm, Taenia solium, and the beef tapeworm, Taenia saginata. Different types of tapeworms have radically different larval stages, which will only be discussed in their specific articles, rather than here.
Adult morphologyAdult tapeworms share a basic body plan. All have a scolex, sometimes colloquially referred to as the "head," a "neck," and one or more proglottids, which are sometimes called "segments," and which are the source of the name "tapeworm," because they look like a strip of tape. The picture at right shows all three components of an adult worm. All cestodes have a nerve ring in the scolex with lateral trunks passing through the rest of the body. ScolexThe Scolex or "head" of the worm attaches to the intestine of the definitive host. In some groups, the scolex is dominated by bothria, which are sometimes called "sucking grooves," and which function like suction cups. Other groups have hooks and suckers that aid in attachment. Cyclophyllidcestodes can be identified by the presence of four suckers on their scolex, though they may have other structures as well. While the scolex is often the most distinctive part of an adult tapeworm, it is often unavailable in a clinical setting, as it is inside the patient. Thus, identifying eggs and proglottids in feces is important. NeckThe Neck of a tapeworm is a relatively undifferentiated mass of cells that divide to form new proglottid "segments." This is where all growth in an adult tapeworm occurs. ProglottidsPosterior to the scolex, they have one or more proglottids that hold the reproductive structures. The sum of the proglottids is called a strobila. It is shaped thin like a strip of tape, which is the source of the common name tapeworm. Like some other flatworms, cestodes use flame cells(protonephridia) for excretion, which are located in proglottids. Mature or gravidproglottids are released from the mature tapeworm and leave the host in its feces. Because each proglottid can reproduce independently, it has been suggested by some biologists that each should be considered a single organism, and that the tapeworm is actually a colony of proglottids. Home RemediesOne of the safest ways to kill tapeworms and other intestinal parasites is to dramatiacally change its environment. This can be done in numerous ways. One is to imbibe much more salt than usual, or just salt and water. It should be noted that when this is done, more water than usual should be taken as the salt will dehydrate the body. Another remedy is to ingest more than the usual amount of spicy food for the person. What might work for one person may not necessarily work for another. The whole point of these methods is to change the enviornment of the parasite, which is the intestine. So making it more salty, or more "spicy" will hopefully change the environment so much for the parasite that it will either try to leave it or die. It should also be noted that a doctor's advice should be taken over anything read here, and should be consulted if possible. These remedies are not necessarily safe nor preferred. Reference
es:Cestodo fr:Cestoda nl:Lintwormen pl:Tasiemce pt:Cestoda simple:Tapeworm sl:Trakulje sv:Bandmask uk:?????????? ?????? zh:??? Categories: Flatworms| Parasitology| Parasites
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