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Median Plane (median + plane)
Selected AbstractsThe effect of whole-body tilt on sound lateralizationEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2002Jörg Lewald Abstract The effect of passive whole-body tilt in the frontal plane on the lateralization of dichotic sound was investigated in human subjects. Pure-tone pulses (1 kHz, 100 ms duration) with various interaural time differences were presented via headphones while the subject was in an upright position or tilted 45° or 90° to the left or right. Subjects made two-alternative forced-choice (left/right) judgements on the intracranial sound image. During body tilt, the auditory median plane of the head, computed from the resulting psychometric functions, was always shifted to the upward ear, indicating a shift of the auditory percept to the downward ear, that is, in the direction of gravitational linear acceleration. The mean maximum magnitude of the auditory shift obtained with 90° body tilt was 25 µs. On the one hand, these findings suggest a certain influence of the otolith information about body position relative to the direction of gravity on the representation of auditory space. However, in partial contradiction to previous work, which had assumed existence of a significant ,audiogravic illusion', the very slight magnitude of the present effect rather reflects the excellent stability in the neural processing of auditory spatial cues in humans. Thus, it might be misleading to use the term ,illusion' for this quite marginal effect. [source] Human perception of verticality: Psychophysical experiments on the centrifuge and their neuronal implicationsJAPANESE PSYCHOLOGICAL RESEARCH, Issue 4 2000Fred W. Mast The role of the otoliths in the perception of verticality is analyzed in two different gravitational environments, 1 g and 1.5 g, and in different roll body positions between upright and upside down. The subjective visual vertical (SVV) is determined when a subject judges the orientation of an indicator as apparently vertical. An increase of g level hardly affects the SVV in the subject's frontal plane (y-z plane). However, for the first time, a three-dimensionally adjustable indicator was used for the SVV and this revealed a new phenomenon: An increase of g level induces a backward slant of the SVV into subject's median plane (x-z plane). The data are discussed with regard to Mittelstaedt's SVV theory; particular emphasis is given to the otolith-head coordinate transformation and the normalization of afferent otolith components. The results of this study provide evidence that the former is implemented at an earlier level and thus precedes the latter. [source] The Morphology of the Cervico-thoracic Sympathetic System in Donkeys (Equus asinus L.)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2009O. Ozgel Summary Five adult donkeys of both sexes, used in applied anatomy classes, and perfused with formalin for teaching purposes, constituted the study material. Ganglion cervicale caudale of the examined materials has observed to exhibit individually variable situation as to extend on the left side of the median line, at the alignment of the first and second intercostal spaces and on the right side between the level of the first and third costa. The ganglion extended more caudally on the right side of median line. The lateral surface of the ganglion was determined to be covered with the m. scalenus medius. On the both sides of the median plane, the ganglion cervicale caudale was seen to be situated on the lateral surface of the m. longus colli. On the left side, the ganglion overlapped the oesophagus in two cadavers and on the right side it was situated within a groove between the m. longus colli and trachea in three cadavers. The rami communicantes received by the ganglion cervicale caudale originated from the eighth cervical and first thoracic spinal segments. The ganglion cervicale caudale was formed by the coalescence of the last cervical and first three thoracic sympathetic ganglia. The ganglion cervicale caudale gave off branches that formed the rami communicantes, plexus cardiacus, n. vertebralis and ansa subclavia. One branch extended from the ganglion to the plexus brachialis. in one specimen, two sympathetic,parasympathetic communicating branches were observed to extend from the ansa subclavia and near by the origin of the truncus sympathicus to the n. vagus. In one of the donkeys examined, a branch originating from the ganglion cervicale caudale on the left side of the median plane was determined to end on the ligamentum arteriosum. A microscopic ganglion structure suggesting the existence of the ganglion cervicale medium was determined in a donkey. [source] Cr1.45Tl1.87Mo15Se19, a monoclinic variant of the hexagonal In3Mo15Se19 typeACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2009P. Gougeon The monoclinic compound Cr1.45Tl1.87Mo15Se19 (chromium thallium pentadecamolybdenum nonadecaselenide) represents a variant of the hexagonal In3Mo15Se19 structure type. Its crystal structure consists of an equal mixture of Mo6Se8Se6 and Mo9Se11Se6 cluster units. The Mo and Se atoms of the median plane of the Mo9Se11Se6 unit, as well as three Cr ions, lie on sites with m symmetry (Wyckoff site 2e). The fourth Cr ion is in a 2b Wyckoff position with site symmetry. [source] Cs2Mo15S19: a novel ternary reduced molybdenum sulfide containing Mo6 and Mo9 clustersACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2004S. Picard The crystal structure of dicaesium pentadecamolybdenum nonadecasulfide, Cs2Mo15S19, consists of a mixture of Mo6S8S6 and Mo9S11S6 cluster units in a 1:1 ratio. Both units are interconnected via inter-unit Mo,S bonds. The Cs+ cations occupy large voids between the different cluster units. The Cs and two inner S atoms lie on sites with 3 symmetry (Wyckoff site 12c) and the Mo and S atoms of the median plane of the Mo9S11S6 cluster unit on sites with 2 symmetry (Wyckoff site 18e). [source] Morphology and morphogenesis of ensiform leaves, syndesmy of shoots and an understanding of the thalloid plant body in species of Apinagia, Mourera and Marathrum (Podostemaceae)BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2005IRMGARD JÄGER-ZÜRN The flattened, irregularly shaped and lobed or dissected leaves of Apinagia riedelii, A. latifolia, A. goejei, Mourera aspera and Marathrum utile (subfamily Podostemoideae) are ensiform in structure. After the typical bifacial inception, further growth of leaves proceeds in the midrib area, i.e. in the median plane of the leaf. The lower leaf zone is characterized by a sheath that orientates ,at the side of the blade', i.e. at the adaxial edge of the sword-like leaf. The ensiform blades are lobed, incised or pinnately dissected with the tips terminated in elongated threads or thin filaments. Leaves of Apinagia riedelii resemble pinnately dissected compound leaves. The dissected structure represents a secondary superimposition of the ensiform shape and a parallel development to compound leaves. It is interpreted as an adaptation to the rapid current, established in the floating shoots of these aquatic plants. The basal portions of main shoots and successive branches are fused due to a retarded separation. Fusion of this kind has been termed a syndesmy. The fused region of shoots is superseded by the fusion of the lower leaf zones of (distichously positioned) adjacent leaves, occurring at their margins. The fused leaf bases form a cavity for the terminal flower bud of each shoot and cover it in the form of a hood. The flower buds are hidden from external view. The meristematic growing zones are thus protected and enclosed within the syndesmic plant body which, in this way, attains the ,thalloid' appearance especially developed in Apinagia goejei and A. latifolia but also present in the other species. The results of this study enable an understanding of the particular appearance of these Podostemoideae as modifications of the typical structures according to the ,principle of variable proportions'. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 147, 47,71. [source] Accessory joints between basiocciput and atlas/axis in the median planeCLINICAL ANATOMY, Issue 8 2005M. von Lüdinghausen Abstract To explore the many osseous irregularities that are found in the area between the basiocciput, the anterior arch of the atlas and the tip of the dens axis we studied 99 cadaver specimens using magnetic resonance tomography (MRT), computed tomography (CT), median saw-cut sections, and histological sections. Additionally, "dry" specimens of the skull (n = 110), atlas (n = 56), and axis (n = 33) were investigated. In the median plane, the dry and cadaver specimens exhibited osteoarthritis-related osseous outgrowths and osteophytes of the articular surfaces of the median atlanto-axial joint (n = 63), and the presence of congenitally developed free ossicles (n = 22) and of third occipital condyles (n = 3). The largest osteophytes (giant osteophytes) (n = 4) of the anterior arch of the atlas formed osseous contact zones with the basiocciput that were visible histologically as real joints and were designated accessory median atlanto-occipital joints. The third occipital condyles also formed osseous contact zones, visible histologically as real joints, with the anterior arch of the atlas or with the tip of the dens, and were designated accessory atlanto-occipital or occipito-odontoid joints. Frequent free ossicles, incorporated into the accessory joint, were found by histological examination to be covered with hyaline cartilage. Clin. Anat. 18:558,571, 2005. © 2005 Wiley-Liss, Inc. [source] | ||||||||||