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Articular Facets (articular + facet)
Selected AbstractsPrezygapophyseal articular facet shape in the catarrhine thoracolumbar vertebral column,AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010Gabrielle A. Russo Abstract Two contrasting patterns of lumbar vertebral morphology generally characterize anthropoids. "Long-backed" monkeys are distinguished from "short-backed" apes [Benton: The baboon in medical research, Vol. 2 (1967:201)] with respect to several vertebral features thought to afford greater spinal flexibility in the former and spinal rigidity in the latter. Yet, discussions of spinal mobility are lacking important functional insight that can be gained by analysis of the zygapophyses, the spine's synovial joints responsible for allowing and resisting intervertebral movements. Here, prezygapophyseal articular facet (PAF) shape in the thoracolumbar spine of Papio, Hylobates, Pongo, Gorilla, and Pan is evaluated in the context of the "long-backed" versus "short-backed" model. A three-dimensional geometric morphometric approach is used to examine how PAF shape changes along the thoracolumbar vertebral column of each taxon and how PAF shape varies across taxa at corresponding vertebral levels. The thoracolumbar transition in PAF shape differs between Papio and the hominoids, between Hylobates and the great apes, and to a lesser extent, among great apes. At the level of the first lumbar vertebra, the PAF shape of Papio is distinguished from that of hominoids. At the level of the second lumbar vertebra, there is variation to some extent among all taxa. These findings suggest that morphological and functional distinctions in primate vertebral anatomy may be more complex than suggested by a "long-backed" versus "short-backed" dichotomy. Am J Phys Anthropol 142:600,612, 2010. © 2010 Wiley-Liss, Inc. [source] Treatment of a prolapsed lumbar intervertebral disc in a ferretJOURNAL OF SMALL ANIMAL PRACTICE, Issue 10 2004D. Lu A seven-month-old, male ferret had acute paraplegia and radiographs showed signs of disc prolapse between the second and third lumbar vertebrae (L2/3). Hemilaminectomy was performed to decompress the spinal cord. Histological examination revealed that the extradural material was consistent with annulus fibrosus and the L2/3 articular facets were enlarged as a result of bone remodelling. The ferret became ambulatory one month postoperatively. Five months postoperatively, the ferret had normal posture with mild proprioceptive deficits in the pelvic limbs, and fusion of the L2 and L3 vertebral bodies. [source] A NEW TITANOSAUR FROM WESTERN SÃO PAULO STATE, UPPER CRETACEOUS BAURU GROUP, SOUTH-EAST BRAZILPALAEONTOLOGY, Issue 1 2006RODRIGO MILONI SANTUCCI Abstract:, Material from a new titanosaur from the Bauru Basin (Bauru Group), Brazil is described and compared with well-known titanosaurs. Adamantisaurus mezzalirai gen. et sp. nov. is based on six articulated anterior caudal vertebrae and two haemapophyses collected from the Adamantina Formation, which is considered to be Campanian,Maastrichtian? in age. Adamantisaurus mezzalirai is characterized by the following combination of characteristics: anterior caudal vertebrae with straight or slightly backwardly-projecting neural spines with strongly expanded distal ends, stout prespinal lamina, very wide pre- and postzygapophyseal articular facets, and concave postzygapophyseal articular facets on anterior caudal vertebrae. Although our cladistic analysis has produced equivocal results, Adamantisaurus mezzalirai shares with DGM ,Series B' (Peirópolis titanosaur) and Aeolosaurus the presence of postzygapophyses with concave articular facets, and shares with DGM ,Series B' the presence of laterally expanded neural spines and stout prespinal lamina. Additionally, A. mezzalirai shares with DGM ,Series' C (other titanosaur from Peirópolis) the presence of short neural spines. [source] Topography and interactions of the arytenoid and cricoid articular facets: Implications for vocal process positional shiftsCLINICAL ANATOMY, Issue 3 2004Kenneth X. Probst Abstract Using new computer applications and digital technologies, we provide a rigorous description and realistic illustrations of the arytenoid-on-the cricoid rotations. We also provide the articular facet topography and interactions that underlay those rotations and the concomitant vocal process positional shifts. The thyroid cartilage and all soft tissues were removed from three excised, preserved, normal, adult human larynges without disturbing the crico-arytenoid (CA) articular capsule. Three CA assemblies were thus prepared and used to digitize arytenoid rotations and vocal process positional shifts, and, after disarticulation, also the surface contour of the arytenoid and cricoid facets, and the cricoid lumen margin. The digitized data served to computer generate 2D and 3D graphic visualizations of the vocal process positional shifts, of the topography of the facets, and of the facet motion sequences that show that the anteroposteriorly concave arytenoid facet slides and conjunctly rotates on the anteroposteriorly convex cricoid facet. Visual details of all graphic representations and facet motion sequences were essentially identical across the three assemblies. Then, based on the computer generated data obtained from the largest of the CA assemblies, 3D, realistic, and hand-drawn images were made that illustrate the directions in which the arytenoids can rotate and the vocal processes concomitantly shift positions. Results indicate that when the arytenoids rotate by sliding from anterior to posterior on the cricoid facets about a primary axis of motion aligned from medial, posterior, and superior, to lateral, anterior, and inferior, their vocal processes shift positions along a plane obliquely oriented from anterior and medial, to posterior and lateral, and from inferior and medial, to superior and lateral. Clin. Anat. 17:206,213, 2004. © 2004 Wiley-Liss, Inc. [source] | ||||||||||