Browsing by Subject "Anatomy"

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Anatomy and anatomical exegesis in Galen of Pergamum
(2013-12) Salas, Luis Alejandro; Dean-Jones, Lesley; Hankinson, R. J.
This dissertation is a study of the differing explanatory criteria used for the assessment of epistemic medical claims, particularly anatomical claims, in the work of Galen of Pergamum (129-c. 216 CE). It focuses on Galen's use of anatomy and anatomical exegesis to position himself in relation to the various medical sects or haireseis active in the Late Roman Empire. Consequent on the emergence of invasive anatomical investigations in the early Hellenistic period (3rd cent. BCE), the explanatory and therapeutic value of anatomical information came to be a defining characteristic of competing medical sects. The Empiricists, who, we are told, were reacting to what they believed was the theoretical promiscuity of other medical thinkers, took their name from their reliance on experience rather than theory, the latter a methodological commitment they attributed to other medical thinkers whom they grouped under the broad category of Dogmatists. This sensitivity to theoretical claims is apparent from the fact that the Empiricists eschewed anatomical dissections, on the grounds that they required analogical moves from structures in corpses to structures in living creatures. If Galen is to be taken at his word, by the second century CE, sectarian disputes between the medical sects had risen to a fever pitch. Galen, who was at pains to make a place for his own medical beliefs in this debate, stresses the need for explanatory theoretical accounts of the body and things relevant to its biological function but also insists that these theoretical accounts be based in empirical observations. One of the arguments he must overcome is the problem of anatomical analogy, raised by the Empiricists. Galen not only engages with this issue from an abstract point of view but, this dissertation argues, he engages with it through the narrative structure of his anatomical accounts throughout his work and especially in his procedural anatomical handbook, De Anatomicis Administrationibus. Historically, this treatise has either been ignored by scholars or studied as a technical treatise that lacks in artifice. This dissertation questions this approach and considers the argumentative role of Galen's anatomical exegesis in the debate over the explanatory value of anatomy in Greco-Roman medicine. It takes as one of its main focuses, Galen's accounts of elephantine anatomy. It argues that these accounts are governed by different norms of assertion, which do not place the same premium on accurate reporting of anatomical detail, from the surrounding anatomical narrative in De Anatomicis Administrationibus. To that end, it shows the need for a more nuanced reading of fachprosa, such as Galen's anatomical work, than these texts have historically received.
Another way to skin a cat : Argument-Driven Inquiry in the human anatomy laboratory
(2018-12) Cheshire, Philip Andrew; Bartholomew, John B.; Sampson, Victor; Griffin, Lisa; Abraham, Lawrence
The demand for healthcare professionals is expected to grow faster than any other industry through 2028. Fundamental to the training and practice of healthcare professionals is human anatomy. However, human anatomy courses experienced substantial declines in time and resources in recent years; reducing anatomical studies to rote memorization. As a result, human anatomy labs often lack best practices in science education, which foster the development of the scientific proficiency that supports the deep learning and reasoning students will need for the high levels of problem-solving in healthcare. PURPOSE: The purpose of this dissertation was to explore the potential for implementing the novel laboratory-teaching framework of Argument-Driven Inquiry (ADI) in the human anatomy laboratory. The research questions related to the feasibility of ADI in anatomy, and the impact that varying levels of ADI had on students' knowledge, reasoning, and perceptions. METHODS: This dissertation conducted three studies. Participants in Studies I and II were 126 and 215 undergraduates respectively. Participants in Study III were 108 first-year medical students. Study I implemented a one-week modified ADI lab in one course section. The subsequent lab exam assessed differences in factual learning compared to the standard labs. Study II implemented a modified ADI lab protocol for the final four weeks of a human anatomy course; using the previous semester's standard protocols as a control group. Factual learning and application reasoning were assessed on the lab exams at the mid-term and final. Study III conducted a medical procedure learning event and assessed factual knowledge changes as well as student perceptions in a pre- and post-test survey. ANALYSIS: For Study I, a 3- way ANOVA tested for mean differences in factual knowledge between lab groups. For Study II, a 3 x 2 mixed factorial MANOVA with repeated measures on the second factor was conducted to test for mean differences in factual knowledge and application reasoning. For Study III, separate one-way repeated-measures ANOVAs tested for mean differences between pre- and post-test factual knowledge and student perceptions. RESULTS: Study I showed no difference in factual knowledge between the modified Argument-driven labs compared to the standard labs. Study II showed no difference in factual knowledge between the intervention and control groups. The intervention group scored significantly higher on the application reasoning assessment. Study III showed no difference between pre- and post-test factual knowledge, and students perceived the medical procedure lab more positively than the standard dissection lab. DISCUSSION: Argument-driven Inquiry is a novel approach that provides a theoretically sound framework for science education. While students report greater engagement, and show improvements in reasoning, there are implementation challenges that restrict its effectiveness at improving factual knowledge and reasoning for a large portion of students. Further research is needed to better understand the factors that allow for more effective implementation, which will allow the impact of ADI in anatomy to be tested in a more robust manner
The comparative osteology and phylogenetic relationships of lepidosirenid lungfishes
(2011-05) Criswell, Katharine Elizabeth; Bell, Christopher J., 1966-; Rowe, Timothy B.; Daeschler, Edward B.
Lepidosirenidae is a clade of freshwater lungfishes that comprise the South American Lepidosiren paradoxa and four African species of the genus Protopterus. These two genera have been geographically separated since the Early Cretaceous break-up of Gondwana, but they share similar biology and skeletal morphology. The lepidosirenid species traditionally were distinguished by a combination of features such as head-to-body ratios, the number of pairs of vertebral ribs, and the presence or absence of external gills, but there are no published discrete skeletal characteristics and no published comparative studies including all extant species. I used High Resolution X-Ray Computed Tomography (CT), X-Ray photography, and alcohol-preserved, cleared-and-stained, and dry skeletal specimens from museum collections to describe the skeletal morphology of all species of lepidosirenid lungfishes in a comparative context. I digitally disarticulated the bones in each CT scan to compile a comprehensive comparative atlas of the cranial and pectoral elements of all extant lungfish. I discovered that the anocleithrum in Lepidosiren paradoxa, which was previously thought to be lacking, is actually present. I also identified skeletal differences between species in the frontoparietal, parasphenoid, supraorbital, and suboperculum. I incorporated those characters into the first morphological phylogenetic analysis to determine the interrelationships of the lepidosirenids. I also used previously published molecular sequence data from the ribosomal RNA gene 16s to run combined morphological and molecular phylogenetic analyses. To generate phylogenetic hypotheses using different types of data and different methods of determining phylogeny, I employed the maximum parsimony, maximum likelihood, and Bayesian inference methods. Lepidosirenidae is monophyletic in almost all analyses, Protopterus is monophyletic in each analysis, and Protopterus annectens and Protopterus aethiopicus are sister taxa in every analysis. The phylogenetic positions of Protopterus dolloi and Protopterus amphibius are incongruent in many of the analyses, which indicates that further examination of the skeletal variation and addition of molecular sequences of different genes is needed. Based on the comparative morphological atlas and the phylogenetic analyses, questions of lepidosirenid biogeography, morphological variation within lungfish, and better identification of lungfish fossils can now be investigated in a more rigorous context.
Cranial osteology of the long-beaked echidna, and the definition, diagnosis, and origin of Monotremata and its major subclades
(2013-12) Simon, Rachel Veronica; Rowe, Timothy, 1953-
Extant monotremes have a combination of plesiomorphic and apomorphic characters that causes ambiguity about their basic anatomy and evolutionary history. The problem is compounded by the lack of extinct and extant specimens of monotremes available for study. Only five species of monotremes are currently recognized, and all are endangered. The most speciose subclade, the long-beaked echidna, Zaglossus, has few specimens archived in mammalogy collections relative to the platypus, Ornithorhynchus anatinus, and the short-beaked echidna, Tachyglossus aculeatus. As a result, researchers sample from Ornithorhynchus and Tachyglossus, excluding species of Zaglossus from analysis. An equally depauperate fossil record consisting primarily of fragmentary jaws and isolated molars over a broad temporal range (~125 Ma) has led to controversies surrounding the origin and evolution of Monotremata and its major subclades. As new fossils attributable to Monotremata have been discovered, they are placed in conflicting positions on either the crown or the stem. I used CT scans of skeletally immature and mature specimens of Zaglossus bruijni and Zaglossus bartoni, respectively, to describe the cranial osteology of Zaglossus in detail. New insights about the anatomy of Zaglossus were then utilized in a phylogenetic analysis. Zaglossus and the extinct echidna, Megalibgwilia were added to a previously published morphological character matrix, along with 42 new skeletal characters. For the first time, I illustrated the cranial anatomy of Zaglossus bruijnii and Zaglossus bartoni, and described the endocranial morphology and individual variation among the two species. I described patterns of ossification throughout ontogeny that may explain a preservation bias against echidnas. My phylogenetic analysis placed the Early Cretaceous monotremes either on the stem of Ornithorhynchidae or in the monotreme crown, supporting an Early Cretaceous divergence estimate between platypuses and echidnas. I provide the first phylogenetic definition and diagnosis of Monotremata, Ornithorhynchidae, and Tachyglossidae. Based on the distribution of characters of extant monotremes, the ancestral monotreme was likely a terrestrial, scratch-digger capable of electroreception. The ancestral population gave rise to the semi-aquatic platypuses and the large, terrestrial echidnas. Tachyglossus is the most derived of the extant echidnas; it is more appropriate to include Ornithorhynchus and Zaglossus in future phylogenetic analyses.
Large clutch of Jurassic mammaliamorph perinates and evolution of mammalian reproduction and growth
(2018-05-03) Hoffman, Eva Amelia; Rowe, Timothy, 1953-; Bell, Christopher J; Colbert, Matthew W
Transformations in morphology, physiology, and behavior along the mammalian stem lineage were accompanied by profound modifications to reproduction and growth, including the emergence of a reproductive strategy characterized by high maternal investment in a small number of offspring and heterochronic changes in early cranial development associated with the enlargement of the brain. Because direct fossil evidence of these transitions is lacking, their timing and sequence are unknown. Here we present the first fossil record of pre- or near-hatching young of any non-mammalian synapsid. A large clutch of well-preserved perinates of the tritylodontid Kayentatherium wellesi (Cynodontia: Mammaliamorpha) were found with a presumed maternal skeleton in Early Jurassic sediments of the Kayenta Formation. The single clutch numbers at least 38 individuals, well outside the range of litter-size variation documented in extant mammals. This discovery confirms that high offspring number is ancestral for amniotes and constrains the timing of a reduction in clutch size along the mammalian stem. Although tiny, the perinates have overall skull shape similar to that of adults, with no allometric lengthening of the face during ontogeny. The only positive allometries are associated with the bones supporting the masticatory musculature. Kayentatherium diverged just before a hypothesized pulse of brain expansion that reorganized cranial architecture at the base of Mammaliaformes. The association of large clutch size with isometric cranial growth is consistent with a scenario in which encephalization—and attendant shifts in metabolism and development—drove later changes to mammalian reproduction.
Reckoning up the body : logics of enumeration and arrangement in Buddhist and Āyurvedic inventories of anatomy
(2013-12) Johnson, Dana Noel; Selby, Martha Ann
Indian accounts of anatomy from the early centuries of the Common Era display a shared desire to enumerate the parts of the human body. Two such accounts occur in the foundational texts of āyurveda --- the Caraka-saṃhitā and Suśruta-saṃhitā --- and another in the Buddhist commentarial text, the Visuddhimagga. Scholars have mined these medical sources in particular to determine the extent and accuracy of anatomical knowledge in ancient India. But little has been done to understand the logics that these sources apply in dismembering, enumerating, and rearranging the body. A close reading reveals three distinct ways by which the materiality of the body could be interpreted in ancient India to conform to broader ideologies and epistemologies. Moreover, through examining both āyurvedic and Buddhist sources, it soon becomes clear that generalizations like "religion" and "medicine" mask the constellation of complex and often-overlapping concerns present in these various studies of anatomy.
The School of Biology
(University of Texas at Austin, 1892-09-21) Waggener, Leslie