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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 207 (1991), S. 157-164 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Neuromast structure in Rana cancrivora larvae was observed by scanning and transmission electron microscopy. Neuromast units, each being composed of two or three neuromasts, are arranged in several well-defined lines in the head, body, and tail regions. The structure of neuromasts in these three regions is basically identical. The neuromast is composed of sensory, sustentacular, and mantle cells. The top of each neuromast has a hillocklike appearance, and is surrounded by four to six epidermal cells with tight intercellular junctions. Long kinocilia and many stereocilia occur in the apex of the neuromasts and are surrounded by numerous microvilli. Numerous granules are present on the apical portions of the mantle and the sustentacular cells. Four or five trapeziform mantle cells are connected closely with each other to form the shell of the neuromast. Large intercellular spaces occur between the mantle cells and the cells of the inner epidermal layers, and between the cells of the inner epidermal layer. Thus, at the apical parts of the neuromast intercellular junctions are tight and the intercellular spaces are more dilated in more basal areas. Morphologically the neuromasts of R. cancrivora larvae resemble those of generalized pond anurans, based on the grouping of Lannoo (Journal of Morphology 191:115-129, 1987a), although larvae of this species inhabit brackish water.
    Additional Material: 5 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 211 (1992), S. 125-135 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Scanning electron microscopy shows that lingual papillae occur all over the dorsal surface of the tongue of the freshwater turtle, Geoclemys reevesii. The surface of each papilla is composed of compactly distributed hemispherical bulges, each composed of a single cell. Microvilli are widely distributed over the surface of cells. Histological examination reveals that the connective tissue penetrates deep into the center of papillae and that the epithelium is stratified columnar. Under the transmission electron microscope, the cells of the basal and the deep intermediate layers of the epithelium appear rounded. A large nucleus lies in the central area of each cell. The cytoplasm contains mitochondria, endoplasmic reticulum and free ribosomes. The cell membrane form numerous processes. The shallow intermediate layer contains two types of cell. The cytoplasm of the first has numerous fine granules, in addition to mitochondria, ribosomes, and endoplasmic reticulum. The other type of cell contains highly electron-dense granules. The surface layer shows two cell types. One type consists of typical mucous cells. The other type of cell contains fine, electron-lucent granules. The latter cells lie on the free-surface side, covering the mucous cells, and have microvilli on their free surfaces.
    Additional Material: 12 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 212 (1992), S. 13-26 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The dorsal surface of the tongue of the little tern, Sterna albifrons, has a distinctive anterior region for five-sixths of its length and a terminal posterior region. The anterior region observed by scanning electron microscopy is distinguished along its forward half by a median line from which median papillae protrude. The hind half of the anterior region has a median sulcus without papillae. The deciduous epithelium on both sides of the median line and sulcus bears scattered epithelial protrusions. The posterior lingual region has neither median papillae nor deciduous epithelium. So-called giant conical papillae are located in a transverse row between anterior and posterior regions. Delicate microridges adorn the surfaces of all outer epithelial cells in both regions.Examination of the dorsal lingual epithelium by light and electron microscopy provides histologic and cytologic criteria for distinguishing anterior and posterior regions. Basal cells are nearly alike throughout the dorsal epithelium. Intermediate layer cells of the anterior region contain numerous tonofibrils in electron-dense bundles composed of 10 nm tonofilaments. The outer layer is composed of electron-dense, well-keratinized cells, and electron-lucent epithelial protrusions are present on the expose surface of the outermost cells. Median papillae are composed of typical keratinized cells, which are nearly filled with keratin filaments. Intermediate layer cells in the posterior region of the tongue are nearly filled with unbundled tonofilaments. There is only a very thin outer keratinized layer in this region.
    Additional Material: 18 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 87 (1976), S. 403-407 
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The content of manganese of the egg ofOryzias latipes was determined by atomic absorption spectrophotometry and activation analysis. The amount of manganese in the unfertilized egg was 0.51 mμg and increased remarkably in one hour after fertilization. Although the increasing rate became gradually lower in further stages, the content of manganese amounted to 2.61 mμg in the embryo after gastrulation. Tracer-experiments showed that the egg accumulated manganese positively from the surrounding medium during the short time after fertilization.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 201 (1989), S. 235-242 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Light and electron microscopic examination of the dorsal lingual epithelium of beagle dogs (Canis domesticus) revealed three different regions: that anterior to the filiform papillae, that posterior to the papillae, and an interpapillary region. Whereas the basal and suprabasal cells are similar throughout, differences characterize the intermediate and surface layers. Keratohyalin granules are common in the intermediate layers in the anterior and interpapillary regions, tonofibrils are prominent in the posterior region, and no keratohyalin granules occur. The surface layer of the interpapillary region is not keratinized, that of the anterior region shows soft keratinization, and that of the posterior region shows hard keratinization. The perimeter of keratohyalin granules is composed of ribosomes 10-20 nm in diameter.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 215 (1993), S. 89-100 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The amphibian tongue contains two types of papilla which are believed to function in gustation and in the secretion of salivary fluid. Scanning electron microscopy reveals that columnar, filiform papillae are compactly distributed over nearly the entire dorsal surface of the tongue of the frog, Rana cancrivora, and fungiform papillae are scattered among the filiform papillae. Microridges and microvilli are distributed on the epithelial cell surface of the extensive area of the filiform papillae. Light microscopy shows that the apex of each filiform papilla is composed of stratified columnar and/or cuboidal epithelium and its base is composed of simple columnar epithelium. Transmission electron microscopy reveals that most of the epithelium of the filiform papillae is composed of cells that contain numerous round electron-dense granules 1-3 μm in diameter. Cellular interdigitation is well developed between adjacent cells. On the free-surface of epithelial cells, microridges or microvilli are frequently seen. Between these granular cells, a small number of ciliated cells, mitochondria-rich cells and electron-lucent cells are inserted. In some cases, electron-dense granules are present in the ciliated cells. At higher magnification, the electron-dense granules appear to be covered with patterns of spots and tubules. Overall, the morphology and ultrastructure of the lingual epithelium of the three species of Rana that have been studied are quite similar, but they can be easily distinguished from those of Bufo japonicus. Therefore, it appears that lingual morphology is phylogenetically constrained among members of the predominantly freshwater genus Rana to produce uniformity of papillary structure and this morphology persists in Rana cancrivora despite the distinct saline environment in which it lives. © 1993 Wiley-Liss, Inc.
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