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dc.contributor.advisorKappelman, John W.en
dc.creatorRyan, Timothy Michaelen
dc.date.accessioned2011-04-04T21:48:57Zen
dc.date.available2011-04-04T21:48:57Zen
dc.date.issued2001-05en
dc.identifier.urihttp://hdl.handle.net/2152/10821en
dc.descriptiontexten
dc.description.abstractIt has been hypothesized for over a hundred years that trabecular bone plays an important structural role in the musculoskeletal system of animals and that it dynamically responds to applied loads through growth. The objectives of this project are to quantify the three-dimensional structure of femoral head trabecular bone in a sample of extant strepsirhines, to test the functional significance of structural variation, and to assess the utility of femoral head trabecular structure for reconstructing the locomotor behavior of extinct primates. The bone volume fraction and fabric anisotropy of trabecular bone in the femoral heads of Cheirogaleus major, Avahi laniger, Galago senegalensis, Galago alleni, Loris tardigradus, Otolemur crassicaudatus, and Perodicticus potto were quantified in three dimensions using serial high-resolution x-ray computed tomography scan data. Significant structural differences were found between the predominantly leaping galagines and indriids and the non-leaping lorisines and cheirogaleids. The leapers in general have relatively anisotropic trabecular bone and the galagines display a unique pattern of increasing anisotropy and decreasing bone volume moving from the superior to the inferior half of the femoral head. By contrast, the non-leaping taxa possess relatively uniform and isotropic bone throughout the femoral head. To test the functional significance of structural differences between the leaping and non-leaping taxa, finite element models of the femoral head trabecular bone in Loris and Galago were constructed. Tissue stresses and strains in the Galago increased as the loading direction shifted from a more superior to a more ventral position, suggesting that the relatively anisotropic bone in this taxon is not optimally designed for significant loads varying off of a generally superoinferior axis. Stress and strain values were higher for both taxa in models with significantly decreased bone volume and connectivity among trabeculae, corroborating the hypothesized structural importance of trabecular bone. Analyses of two Eocene primate taxa – Omomys carteri and Shoshonius cooperi – demonstrate the utility of trabecular bone analyses for determining the possible locomotor behaviors of extinct taxa. Omomys has trabecular bone most similar to modern generalized quadrupedal forms like P. potto while Shoshonius has trabecular bone most like that of the leaping galagos.
dc.format.mediumelectronicen
dc.language.isoengen
dc.rightsCopyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.en
dc.subjectPrimatesen
dc.subjectOsteoporosis--Diagnosisen
dc.subjectBone densitometryen
dc.subjectFemuren
dc.titleThe structure and function of trabecular bone in the femoral head of strepsirhine primatesen
dc.description.departmentAnthropologyen
thesis.degree.departmentAnthropologyen
thesis.degree.disciplineAnthropologyen
thesis.degree.grantorThe University of Texas at Austinen
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen
dc.rights.restrictionRestricteden


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