Morphologie Et Embryologie PDF Download

Author:
Publisher:
ISBN:
Category : Abnormalities, Human
Languages : en
Pages : 418

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Author: National Library of Medicine (U.S.)
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 1118

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A keyword listing of serial titles currently received by the National Library of Medicine.

Author: National Library of Medicine (U.S.)
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 1170

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First multi-year cumulation covers six years: 1965-70.

Author: Robert M. Pigache
Publisher: Springer Science & Business Media
ISBN: 364265004X
Category : Medical
Languages : en
Pages : 64

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The prime purpose of this paper is to look at the region of brain which many authors call 'paleocortex' and to ask how much of the area it embraces can be described properly as cortex. Before this can be considered it is necessary to have some idea of what constitutes a cortex. Therefore, in the first part of the paper the criteria used in constructing classifications of cortex are looked into. Also considered is the meaning of classifications such as 'paleocortex'. Is it relevant to define cortex in this way? How does this view correlate with a functional approach? The second purpose of this paper, of equal importance to the first, is to review terminology. Each area of' paleocortex' has a review introduction that endeavoors to cut through the existing jungle of terms and usage and to provide a clear account of the area in question, prior to examining its standing as cortex. The term 'paleocortex' is in common use and for this reason it is worth close examination. Kappers (1909) first created the term to supplement the earlier division of cortex-into archicortex and neocortex-introduced by Elliot Smith. Kappers applied the term to the mantle layer of the most primitive vertebrates (cyclostomes and selachians), the whole of which receives secondary olfactory fibres.

Author: Radomir Cihak
Publisher: Springer Science & Business Media
ISBN: 3662090813
Category : Medical
Languages : en
Pages : 194

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The aim of the present publication is to summarize the results of studies of ontogenesis of the skeleton and muscles of the human hand and foot. Our primary interest in studying the muscles arose from observations of variations, in which a new form of the anomalous muscle in the popliteal fossa had been described (Cihak, 1954; Hnevkovsky and Cihak, 1957) and in which changes of muscle forms in the congenitally malformed extremity had also been studied (Brlickova and Cihak, 1956). The desire to clarify muscle variations by means of the onto genesis led to a study of ontogenesis of single muscles. During observation of the embryonic pectoralis major special muscle bundles were primarily observed, which could be homologised with the sphincter colli muscle of lower Mammals. Further observation revealed that this muscle (concordantly with its phylo genetic development) gradually develops in the course of human ontogenesis from a small primordium to its maximal extent and becomes reduced thereafter and finally disappears, still during the embryonic period (Cihak, 1957). This study was decisive for the further development of our theme, since it demonstra tes, how consistently in the development of the locomotor apparatus the rule of recapitulation is asserted and how this can be employed in developmental studies of muscles.

Author: I.R. Phillips
Publisher: Springer Science & Business Media
ISBN: 3642664962
Category : Science
Languages : en
Pages : 47

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The primates represent a diverse group with the phylogenetic relationships of the var ious species reflected in their early embryonic development. The members of the Tupaiidae, Lemuridae and Lorisidae show great similarities to the lower mammals and even birds. The Tarsiidae represent an intermediate step and the Platyrrhini and Catarrhini exhibit the greatest similarities to man. During the period of embryogenesis, the dimensions of an embryo are insufficient guide to its age and much more reliable information can be derived from a study of its external form and internal structure. Examination of embryological specimens from a variety of simian species dates back to the early 1900's but much of this material was collected in a haphazard way from animals shot in the wild. Heuser and Streeter (1941) depicted a series of embryos of the rhesus monkey (Macaca mulatta) and correlated their gestational age with external form and size. Streeter (1951) arranged human em bryos, between 24. ± 1 and 47. ± 1 days of post-ovulation age, into age groups or devel opmental horizons based on their external form and internal structure. Each horizon was two days apart and numbered XI to XXIII. The transition from embryo to fetus occurred at the end of horizon XXIII and was arbitrarily dermed as the point where bone marrow invaded the cartilaginous precursor in the humerus. The earlier stages I-X have been dermed subsequently, (Heuser and Corner, 1957; O'Rahilly, 1973).

Author: M. E. Molliver
Publisher: Springer Science & Business Media
ISBN: 3642516319
Category : Medical
Languages : en
Pages : 54

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The ontogenesis of cortical circuitry is the subject of the investigation reported in this paper!. Strategie elements of cortical circuitry are synaptic contacts: sites of neuronal interaction. If we first determine the location of early formed synap ses, we may then seek the pre-and postsynaptic elements, that is, the structures which meet and interact at each synaptic junction. The dynamic aspects of cortical development cannot be studied directly: neuronal growth cannot be observed in an intact brain. The pattern of develop ment can be approached only by the analysis of static properties at multiple ages. We have selected the newborn dog as a starting point for these studies. Our observations have been restricted to a small portion of primary somesthetic cor tex. This region was selected because, in mature cortex, its input and physiologie properties are relatively weIl known. It is particularly advantageous to study a primary sensory projection area because its morphologie development can be di rectly related to its functional development. (A related investigation of the onto genesis of electrical activity in somesthetic cortex of the dog will be reported separately). A selective review of the literature is necessary in order to place this work in the context of a few relevant phenomena of cortical development.

Author: Finn-Mogens Smejda Haug
Publisher: Springer Science & Business Media
ISBN: 3642515851
Category : Medical
Languages : en
Pages : 71

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The importance of transition metals and group II b metals in biological reac tions is becoming increasingly clear. Such metals form an integral part of the structure of many enzymes and non-enzymic proteins and also feature in more reversible interactions between metal ions and large or small biological molecules (Johnson and Seven, 1961). As discussed at the end of this paper, chemical analyses have shown the presence of these metals in the central nervous system and some hypotheses have been advanced concerning their role in more specific nervous activities such as synaptic processes. In order to define more precisely the role of these trace metals it is clearly necessary to investigate their regional and cytological distribution, as may be achieved by the use of histochemical methods. Some of the earliest neurohistochemical studies were concerned with trace metals, especially iron, in the brain (Spatz, 1922). Later reports on the localiza tion of trace metals have been comparatively few, except as regards the hippo campal region. Maske's report (1955) that intravital injections of the coloured chelating agent, dithizone, revealed an accumulation of zinc within the hippocampus, prompted aseries of investigations by Fleischhauer and Horstmann (1957), Timm (1958a), McLardy (1960, 1962, 1963, 1964), von Euler (1962), and others, in which the intravital dithizone method or Timm's sulphide silver method was used. As a result, particularly intense staining was found to correspond to the zones receiving mossy fibre terminals (Cajal, 1911; Blackstad et al., 1970).

Author: H. Aldskogius
Publisher: Springer Science & Business Media
ISBN: 3642658679
Category : Medical
Languages : en
Pages : 78

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In the previous study (Part I) a description was given of the ultrastructural changes occurring during indirect Wallerian degeneration in the intramedullary root fibre region of the kitten hypoglossal nerve. One of the striking features of this degeneration process was the appearance at an early stage of micro glial cells completely covered by myelin, which apparently participated in phago cytosis of degenerating axoplasm and to a small extent of their own myelin covering. Evidence was obtained indicating that the numerous degenerating glial cells seen somewhat later in the degeneration process were derived from these myelin-covered microglial cells. Since glial cells of the type described in the previous study have never been implicated in the process of direct Wallerian degeneration, the possibility exists that they may in fact be characteristic for indirect Wallerian degeneration. However, this possibility cannot be adequately assessed unless our present rather scanty knowledge concerning the early glial reaction during direct Wallerian degeneration is extended. Therefore the present study has been undertaken to examine the ultrastructural changes during direct W allerian degeneration in the kitten, with particular reference to the possible occurrence of myelin-covered microglial cells and degenerating glial cells of the type described in the previous study (see Part I). Since no systematic ultra structural study on direct Wallerian degeneration in immature animals seem to exist, observations on changes in the myelinated nerve fibres and the different types of glial cells have been included.

Author: J. Kartenbeck
Publisher: Springer Science & Business Media
ISBN: 3662103907
Category : Medical
Languages : en
Pages : 55

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During the past twenty years the structure of the nuclear envelope, and in particular, that of its most distinct elements, the nuclear pore complexes, has been described from thin section electron microscopy (e, g., Brettschneider, 1952; Hartmann, 1953; Bahr and Beermann, 1954; Watson, 1954; Kautz and de Marsh, 1955; Watson, 1955), from metal-shadowed (e. g., Callan and Tomlin, 1950; Gall, 1954, 1956) and negatively stained (e. g., Franke, 1966, 1967; Gall, 1967; Yoo and Bayley, 1967) preparations of isolated nuclear membranes as revealing characte ristics common to euka. ryotic cells in general (recently reviewed, e. g., in Gouran ton, 1969; Stevens and Andre, 1969; Franke, 1970). In the recent years the freeze-etch technique (Steere, 1957) has proved to be a particularly useful tool in studying membraneous structures (e. g., Moor and Miihlethaler, 1963; Branton and Moor, 1964; Branton, 1966; Koehler, 1968b; Staehelin, l968a; Northcote, 1968a; Branton, 1969; Moor, 1969a). So this method has especially broadened the knowledge, e. g., on bacterial membranes (Bayer and Remsen, 1970; Nanninga, 1970), on erythrocyte plasma membranes (Weinstein and Bullivant, 1967; Meyer and Winkelmann, 1970; da Silva and Branton, 1970; Tillack and Marchesi, 1970), on liver cell membranes (Chalcroft and Bullivant, 1970), on Golgi membranes (Werz and Kellner, 1970; Staehelin and Kiermayer, 1970), on synaptic vesicles (Moor et al.