Examination Date
Spring 3-24-2025
Degree
Dissertation
Degree Program
Cell Biology and Anatomy
Examination Committee
Emma R. Schachner, Sonya Van Nuland, Deidre J. Devier, Hamilton Farris, Brandon P. Hedrick
Abstract
Despite being a region of interest to biologists for centuries, the avian respiratory system remains a poorly understood vertebrate organ system. Most of what is known about the anatomy of the avian respiratory system has previously been investigated using latex or silicone injections and/or gross dissection. The overarching objective of this work is to address questions about the functional respiratory anatomy in multiple extant avian species using micro-computed tomography (mCT) scan data to visualize and create 3D surface models of in vivo and in situ relationships of the respiratory system with adjacent soft and skeletal tissues. This dissertation contributes original research on this unique respiratory system by: 1) modeling and describing the respiratory anatomy of the Zebra Finch (Taeniopygia castanotis) and examining the potential morphological constraints on the inspiratory valving mechanism; 2) assessing the variability in postcranial pneumaticity across five avian taxa with regard to which pulmonary tissues are responsible for pneumatizing certain regions of the postcranial skeleton; and, 3) examining the gross morphological and volumetric effects of obesity on the avian respiratory system. Broadly, the findings of this dissertation reveal: 1) a complete 3D digital model of the lung and air sac system in the Zebra Finch, including the parabronchial segments within the paleopulmo; 2) that the source of pneumatizing tissues is both inter- and intraspecifically variable and cannot be estimated by examining skeletal tissues alone; and 3) excess intracoelomic adipose tissue causes substantial compression of caudal air sacs and diverticula, a pathology that cannot by reliably evaluated using traditional body condition scoring systems. This analysis collectively suggests a need to reassess assumptions of consistency and variability in respiratory anatomy across Aves that have previously supported broad inferences about respiratory function, interactions with adjacent soft and skeletal tissues, and its evolution.
Recommended Citation
Martinez, Aracely, "MORPHOLOGY OF THE RESPIRATORY SYSTEM IN THE ZEBRA FINCH (Taeniopygia castanotis) AND THE RELATIONSHIP BETWEEN THE LUNGS AND ADJACENT ORGANS IN OTHER AVIAN TAXA" (2025). School of Graduate Studies. 17.
https://digitalscholar.lsuhsc.edu/etd_sgs/17
Dissertation Report Form