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Dwarf Tapeworm
Dwarf tapeworm (''Hymenolepis nana'', also known as ''Rodentolepis nana'', ''Vampirolepis nana'', ''Hymenolepis fraterna'', and ''Taenia nana'') is a cosmopolitan species though most common in temperate zones, and is one of the most common cestodes (a type of intestinal worm or helminth) infecting humans, especially children. Morphology As its name implies ( grc, νᾶνος, nānos – dwarf), it is a small species, seldom exceeding 40 mm long and 1 mm wide. The scolex bears a retractable rostellum armed with a single circle of 20 to 30 hooks. The scolex also has four suckers, or a tetrad. The neck is long and slender, and the segments are wider than long. Genital pores are unilateral, and each mature segment contains three testes. After apolysis, gravid segments disintegrate, releasing eggs, which measure 30 to 47 µm in diameter. The oncosphere is covered with a thin, hyaline, outer membrane and an inner, thick membrane with polar thickenings that bear sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodor Bilharz
Theodor Maximilian Bilharz (23 March 1825 – 9 May 1862) was a German physician who made pioneering discoveries in the field of parasitology. His contributions led to the foundation of tropical medicine. He is best remembered as the discoverer of the blood fluke ''Schistosoma haematobium'', the causative parasite of bloody urine (haematuria) known since ancient times in Egypt. The parasite, as the cause of bladder cancer, is declared by the International Agency for Research on Cancer as Group 1 carcinogen. The infection is known by an eponymous term bilharzia or bilharziasis, as well as by schistosomiasis. Bilharz was born and educated in Sigmaringen, Hohenzollern-Sigmaringen, Germany. After graduating in natural science and philosophy from the Albert-Ludwigs-Universität in 1845, he earned a medical degree from the University of Tübingen in 1849. In 1850, he followed his former teacher Wilhelm Griesinger to Egypt to work at the Qasr El Eyni Hospital in Cairo. He became t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brayton H
Brayton may refer to: People * Brayton (name) * Sir Wilfrid Lawson, 1st Baronet, of Brayton * Sir Wilfrid Lawson, 2nd Baronet, of Brayton * Sir Wilfrid Lawson, 3rd Baronet, of Brayton * Sir Hilton Lawson, 4th Baronet Church * Brayton Church Ahlone, Yangon, Myanmar Places * Brayton, Iowa, a city in the United States * Brayton, Nebraska * Brayton, New South Wales, a small village in Australia * Brayton Hall, Cumbria, England ** Brayton railway station, Cumbria, England * Brayton, North Yorkshire, a small village in England ** Brayton Academy, formerly Brayton High School, a high school in Selby, North Yorkshire, England * Brayton Grist Mill, an historic grist mill in Pomfret, Connecticut * Brayton Fire Training Field, a firefighter training field in College Station, Texas * Brayton Methodist Episcopal Church, an historic church in Fall River, Massachusetts * 32571 Brayton, a Main-belt Asteroid and named after Scott Brayton * Bailey-Brayton Field, a college baseball stadium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cestodes
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 fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helminth
Parasitic worms, also known as helminths, are large macroparasites; adults can generally be seen with the naked eye. Many are intestinal worms that are soil-transmitted and infect the gastrointestinal tract. Other parasitic worms such as schistosomes reside in blood vessels. Some parasitic worms, including leeches and monogeneans, are ectoparasites thus, they are not classified as helminths, which are endoparasites. Parasitic worms live in and feed in living hosts. They receive nourishment and protection while disrupting their hosts' ability to absorb nutrients. This can cause weakness and disease in the host, and poses a global health and economic problem. Parasitic worms cannot reproduce entirely within their host's body; they have a life cycle that includes some stages that need to take place outside of the host. Helminths are able to survive in their mammalian hosts for many years due to their ability to manipulate the host's immune response by secreting immunomodulatory ... [...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 fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostellum (helminth)
Rostellum (meaning "small beak", from the Latin ' for " beak"; pl. rostella) in helminthology is a protruding part of the anterior end of tapeworms. It is a retractable, cone-like muscular structure that is located on the apical end of the scolex, and in most species is armed with hooks, the organs of attachment to the host's intestinal wall. It is a parasitic adaptation in some cestodes for firm attachment in the gastrointestinal tract and is structurally different from one species to another (or even absent is some species), thereby becoming an important diagnostic feature. Structure A rostellum is a knob-like protrusion at the extreme anterior end of a tapeworm, as an extension of the tegument. It is globular, spiny structure when it protrudes, and a circular hollow pit when retracted. It is structurally composed of a number of concentric rows of hooks. The number and arrangement of the hooks are species specific. The two basic types of hooks are those of the upper row, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apolysis
Apolysis ( grc, ἀπόλυσις "discharge, lit. absolution") is the separation of the arthropod cuticle, cuticle from the Epidermis (zoology), epidermis in arthropods and related groups (Ecdysozoa). Since the cuticle of these animals is also the skeletal support of the body and is inelastic, it is shed during growth and a new covering of larger dimensions is formed. During this process, an arthropod becomes dormant for a period of time. Enzymes are secreted to digest the inner layers of the existing cuticle, detaching the animal from the outer cuticle. This allows the new cuticle to develop without being exposed to the environmental elements. After apolysis, ecdysis occurs. Ecdysis is the actual emergence of the arthropod into the environment and always occurs directly after apolysis. The newly emerged animal then hardens and continues its life. References {{reflist Developmental biology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strobila
Strobilisation or transverse fission is a form of asexual reproduction consisting of the spontaneous transverse segmentation of the body. It is observed in certain cnidarians and helminths. This mode of reproduction is characterized by high offspring output, which, in the case of the parasitic tapeworms, is of great significance. Strobilation in cnidarians *The process starts with preliminary morphological changes. In particular, the cnidarian's tentacles tend to be reabsorbed. *Neck-formation: transverse constrictions appear near the upper extremity of the animal. A strobilating polyp is called a strobila while the non-strobilating polyp is called a scyphistoma or scyphopolyp. *Segmentation: the number of constriction sites increases and migrates down the body length, transforming the body into a sequence of disks. The fissures intensify until the initial body is divided into equally spaced, separate segments. The oral end of the polyp becomes the oral end of the ephyra. *Metamorph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H Nana LifeCycle
H, or h, is the eighth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''aitch'' (pronounced , plural ''aitches''), or regionally ''haitch'' ."H" ''Oxford English Dictionary,'' 2nd edition (1989); ''Merriam-Webster's Third New International Dictionary of the English Language, Unabridged'' (1993); "aitch" or "haitch", op. cit. History The original Semitic letter Heth most likely represented the voiceless pharyngeal fricative (). The form of the letter probably stood for a fence or posts. The Greek Eta 'Η' in archaic Greek alphabets, before coming to represent a long vowel, , still represented a similar sound, the voiceless glottal fricative . In this context, the letter eta is also known as Heta to underline this fact. Thus, in the Old Italic alphabets, the letter Heta of the Euboean alphabet was adopted with its original sound value . While Etruscan and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H Nana EggB
H, or h, is the eighth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''aitch'' (pronounced , plural ''aitches''), or regionally ''haitch'' ."H" ''Oxford English Dictionary,'' 2nd edition (1989); ''Merriam-Webster's Third New International Dictionary of the English Language, Unabridged'' (1993); "aitch" or "haitch", op. cit. History The original Semitic letter Heth most likely represented the voiceless pharyngeal fricative (). The form of the letter probably stood for a fence or posts. The Greek Eta 'Η' in archaic Greek alphabets, before coming to represent a long vowel, , still represented a similar sound, the voiceless glottal fricative . In this context, the letter eta is also known as Heta to underline this fact. Thus, in the Old Italic alphabets, the letter Heta of the Euboean alphabet was adopted with its original sound value . While Etruscan and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostellum
The rostellum is a projecting part of the column in Orchidaceae flowers, and separates the male androecium from the female gynoecium, commonly preventing self-fertilisation. In many orchids, such as ''Orchis mascula'', the pollinia or pollen masses, are connected by stipes down to adhesive discs attached to the rostellum which forms cups keeping the discs or balls sticky. In ''Catasetum'' flowers the rostellum projects forward at each side as an "antenna", and the pollen masses are connected by a bent stalk or pedicel to a sticky disc kept moist at the back of the flower. When an insect touches an "antenna", this releases the bent pedicel which springs straight and fires the pollinium, sticky disc first, at the insect. Charles Darwin described in ''Fertilisation of Orchids ''Fertilisation of Orchids'' is a book by English naturalist Charles Darwin published on 15 May 1862 under the full explanatory title ''On the Various Contrivances by Which British and Foreign Orchids Ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
