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Cysticercoid
A cysticercoid is the larval stage of certain tapeworms, similar in appearance to a cysticercus, but having the scolex filling completely the enclosing cyst. In tapeworm infections, cysticercoids can be seen in free form as well as enclosed by cysts in biological tissues such as the intestinal mucosa. Also referred to as metacestodes, they produce proteins enabling them to invade and to survive in the host. * Cysticercosis * Hymenolepiasis Hymenolepiasis is infestation by one of two species of tapeworm: '' Hymenolepis nana'' or '' H. diminuta''. Alternative names are dwarf tapeworm infection and rat tapeworm infection. The disease is a type of helminthiasis which is classified as a ... References Cestoda Larvae {{parasitic animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larval Stage
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The larva's appearance is generally very different from the adult form (''e.g.'' caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the larval stage will consume food to fuel their transition into the adult form. In some organisms like polychaetes and barnacles, adults are immobil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tapeworm
Eucestoda, commonly referred to as tapeworms, is the larger of the two subclasses of flatworms in the class Cestoda (the other subclass is Cestodaria). Larvae have six posterior hooks on the scolex (head), in contrast to the ten-hooked Cestodaria. All tapeworms are endoparasites of vertebrates, living in the digestive tract or related ducts. Examples are the pork tapeworm (''Taenia solium'') with a human definitive host, and pigs as the secondary host, and '' Moniezia expansa'', the definitive hosts of which are ruminants. Body structure Adult Eucestoda have a white-opaque dorso-ventrally flattened appearance, and are elongated, ranging in length from a few millimeters to 25 meters. Almost all members, except members of the orders Caryophyllidea and Spathebothriidea, are polyzoic with repeated sets of reproductive organs down the body length, and almost all members, except members of the order Dioecocestidae, are protandral hermaphrodites. Most except caryophyllideans c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysticercus
Cysticercus (pl. cysticerci) is a scientific name given to the young tapeworms (larvae) belonging to the genus '' Taenia''. It is a small, sac-like vesicle resembling a bladder; hence, it is also known as bladder worm. It is filled with fluid, in which the main body of the larva, called scolex (which will eventually form the head of the tapeworm), resides. It normally develops from the eggs, which are ingested by the intermediate hosts, such as pigs and cattle. The tissue infection is called cysticercosis. Inside such hosts, they settle in the muscles. When humans eat raw or undercooked pork or beef that is contaminated with cysticerci, the larvae grow into adult worms inside the intestine. Under certain circumstances, specifically for the pork tapeworm, the eggs can be accidentally eaten by humans through contaminated foodstuffs. In such case, the eggs hatch inside the body, generally moving to muscles as well as inside the brain. Such brain infection can lead to a serious medical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scolex
Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of many similar units known as proglottids—essentially packages of eggs which are regularly shed into the environment to infect other organisms. Species of the other subclass, Cestodaria, are mainly fish infecting parasites. All cestodes are parasitic; many have complex life histories, including a stage in a definitive (main) host in which the adults grow and reproduce, often for years, and one or two intermediate stages in which the larvae develop in other hosts. Typically the adults live in the digestive tracts of vertebrates, while the larvae often live in the bodies of other animals, either vertebrates or invertebrates. For example, ''Diphyllobothrium'' has at least two intermediate hosts, a crustacean and then one or more freshwater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Tissue
In biology, tissue is a biological organizational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues. The English word "tissue" derives from the French word "tissu", the past participle of the verb tisser, "to weave". The study of tissues is known as histology or, in connection with disease, as histopathology. Xavier Bichat is considered as the "Father of Histology". Plant histology is studied in both plant anatomy and physiology. The classical tools for studying tissues are the paraffin block in which tissue is embedded and then sectioned, the histological stain, and the optical microscope. Developments in electron microscopy, immunofluorescence, and the use of frozen tissue-sections have enhanced the detail that can be observed in tissues. With these tools, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intestinal Mucosa
The gastrointestinal wall of the gastrointestinal tract is made up of four layers of specialised tissue. From the inner cavity of the gut (the lumen) outwards, these are: # Mucosa # Submucosa # Muscular layer # Serosa or adventitia The mucosa is the innermost layer of the gastrointestinal tract. It surrounds the lumen of the tract and comes into direct contact with digested food ( chyme). The mucosa itself is made up of three layers: the epithelium, where most digestive, absorptive and secretory processes occur; the lamina propria, a layer of connective tissue, and the muscularis mucosae, a thin layer of smooth muscle. The submucosa contains nerves including the submucous plexus (also called Meissner's plexus), blood vessels and elastic fibres with collagen, that stretches with increased capacity but maintains the shape of the intestine. The muscular layer surrounds the submucosa. It comprises layers of smooth muscle in longitudinal and circular orientation that also hel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysticercosis
Cysticercosis is a tissue infection caused by the young form of the pork tapeworm. People may have few or no symptoms for years. In some cases, particularly in Asia, solid lumps of between one and two centimetres may develop under the skin. After months or years these lumps can become painful and swollen and then resolve. A specific form called neurocysticercosis, which affects the brain, can cause neurological symptoms. In developing countries this is one of the most common causes of seizures. Cysticercosis is usually acquired by eating food or drinking water contaminated by tapeworms' eggs from human feces. Among foods egg-contaminated vegetables are a major source. The tapeworm eggs are present in the feces of a person infected with the adult worms, a condition known as taeniasis. Taeniasis, in the strict sense, is a different disease and is due to eating cysts in poorly cooked pork. People who live with someone with the pork tapeworm have a greater risk of getting cysticerc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hymenolepiasis
Hymenolepiasis is infestation by one of two species of tapeworm: '' Hymenolepis nana'' or '' H. diminuta''. Alternative names are dwarf tapeworm infection and rat tapeworm infection. The disease is a type of helminthiasis which is classified as a neglected tropical disease. Symptoms and signs Hymenolepiasis does not always have symptoms, but they usually are described as abdominal pain, loss of appetite, itching around the anus, irritability, and diarrhea. However, in one study of 25 patients conducted in Peru, successful treatment of the infection made no significant difference to symptoms. Some authorities report that heavily infected cases are more likely to be symptomatic. Symptoms in humans are due to allergic responses or systematic toxaemia caused by waste products of the tapeworm. Light infections are usually symptomless, whereas infection with more than 2000 worms can cause enteritis, abdominal pain, diarrhea, loss of appetite, restlessness, irritability, restless sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cestoda
Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of many similar units known as proglottids—essentially packages of eggs which are regularly shed into the environment to infect other organisms. Species of the other subclass, Cestodaria, are mainly fish infecting parasites. All cestodes are parasitic; many have complex life histories, including a stage in a definitive (main) host in which the adults grow and reproduce, often for years, and one or two intermediate stages in which the larvae develop in other hosts. Typically the adults live in the digestive tracts of vertebrates, while the larvae often live in the bodies of other animals, either vertebrates or invertebrates. For example, ''Diphyllobothrium'' has at least two intermediate hosts, a crustacean and then one or more freshwater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
