Hyperbaric tracheobronchial compression in cetaceans and pinnipeds
| Autor: | Sophie Dennison-Gibby, Michael A. Denk, Zhongchang Song, Andreas Fahlman, Michael J. Moore |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Common dolphin Physiology Seals Earless Common Dolphins Diving Aquatic Science 010603 evolutionary biology 01 natural sciences Decompression sickness 03 medical and health sciences Marine mammal biology.animal Phocoena Pressure Medicine Animals Molecular Biology Ecology Evolution Behavior and Systematics Harp seal 030304 developmental biology 0303 health sciences biology business.industry Anatomy respiratory system biology.organism_classification medicine.disease respiratory tract diseases Trachea Insect Science Respiratory Mechanics Harbor seal Animal Science and Zoology business Airway Lung inflation Porpoise |
| Zdroj: | The Journal of experimental biology. 223(Pt 5) |
| ISSN: | 1477-9145 |
| Popis: | Assessment of the compressibility of marine mammal airways at depth is crucial to understanding vital physiologic processes such as gas exchange during diving. Very few studies have directly assessed changes in cetacean and pinniped trachea-bronchial shape, and none have quantified changes in volume with increasing pressure. A freshly deceased harbor seal, grey seal, harp seal, harbor porpoise, and common dolphin were imaged post mortem via CT in a radiolucent hyperbaric chamber as previously described in Moore et al (2011). Volume reconstructions were performed of segments of the trachea and bronchi of the pinnipeds and bronchi of the cetaceans for each pressure treatment. All specimens examined demonstrated significant decreases in volume with increasing pressure, with the harbor seal and common dolphin nearing complete collapse at the highest pressures. The common dolphin bronchi demonstrated distinctly different compression dynamics between 50% and 100% lung inflation treatments, indicating the importance of air in maintaining patent airways, and collapse occurred caudally to cranially in the 50% treatment. Dynamics of the harbor seal and grey seal airways indicated that the trachea was less compliant than the bronchi. These findings indicate potential species-specific variability in airway compliance, and cessation of gas exchange may occur at greater depths than those predicted in models assuming rigid airways. This may potentially increase the likelihood of decompression sickness in these animals during diving. |
| Databáze: | OpenAIRE |
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