Integrative Biomechanics of Marine Mammals; Adaptations for Feeding, Diving, and Hearing in Whales

我们从工程学和物理学的角度研究动物是如何工作的。新的工作将集中在海洋哺乳动物，主要是须鲸。经过几十年的商业开发和无数的研究机会，直到最近，它们的解剖和生物力学细节仍然模糊不清。在最近成功的基础上，我们的发现研究旨在进一步了解支持它们水生生活方式的解剖、生理和生物力学适应。我们将使用解剖学，组织生物力学，计算机和数字建模来推断四个关键领域的生理功能：弓步喂养，流体动力学，能量学。吞食的水动力和代谢模型将按照过去对鱼尾研究的方法，用灵活的、比例模型的量化水动力性能来改进。将结果与计算流体动力学相结合，通过添加不同体型和速度的流体动力阻力的实际成本，将为数学能量预算模型提供信息。循环系统设计用于游泳和潜水时的快速压力变化。通过现场测量的心率数据，我们将重新审视旧的中央循环血液动力学模型，看看在潜水过程中如何优化血流。我们将从死后病例中研究胸腔和颅血管视网膜的力学特性和3D结构，然后使用数学模型来验证视网膜如何在内部压力快速变化时保护大脑免受流动瞬变的假设。呼吸系统设计和肺塌陷。我们将讨论鼻塞和喷孔如何保护上呼吸道免受水侵入，以及吞咽时特殊的咽结构如何保护正常上呼吸道免受食物的侵害。我们将继续对许多物种的下气道结构的形态学和力学进行比较研究，使用肺膨胀、CT扫描的3D肺和气管解剖、显微镜和肺泡组成来确定肺在呼吸和深度塌陷时如何排空。基于高压CT扫描，我们将创建一个胸腔压缩的有限元模型，以了解胸壁和隔膜变形如何在深度上压缩肺部，并在胸腔和胸、颅视网膜之间转移血容量。内耳结构和听力。我们现在知道如何对耳蜗毛细胞进行成像，并绘制了第一张鲸鱼（白鲸）耳蜗的空间频率图，目的是将搁浅人员的损伤与特定声源联系起来。我们计划在其他物种上进行类似的工作，包括听力能力未知的鸟。我们的鲸鱼生物力学研究项目将对大型鲸鱼的游泳、潜水和进食，以及它们对这些功能的解剖和生理适应进行最全面和定量的研究。

We study how animals work from an engineering and physics perspective. New work will focus on marine mammals, principally rorqual baleen whales. After decades of commercial exploitation with countless opportunities for study, details of their anatomy and biomechanics remained obscure until lately. Building on recent successes, our discovery research seeks to further our understanding of anatomical, physiological, and biomechanical adaptations that support their aquatic lifestyle. We will use anatomy, tissue biomechanics, and computer and digital modelling to infer physiological function in four key areas:    Lunge feeding hydrodynamics, energetics. Hydrodynamic and metabolic models of engulfment will be refined with quantified hydrodynamic performance of flexible, scaled models of rorqual tail flukes, following methods from past studies of fish tails. Combining results with computational fluid dynamics will inform mathematical energy budget models by adding realistic costs of hydrodynamic drag forces for different body sizes and speeds.     Circulatory system design for rapid pressure changes during swimming and diving. With field measured heart rate data from a collaboration, we will revisit our old hemodynamic model of the central circulation to see how flow is optimized during a dive. We will study the mechanical properties and 3D structure of thoracic and cranial vascular retia from post-mortem cases, and then use mathematical modelling to test hypotheses of how retia protect the brain from flow transients during rapid changes in internal pressures.    Respiratory system design and lung collapse at depth. We will address how nasal plugs and blowhole protect the upper airway from water incursion and how special pharyngeal structures protect the rorqual upper airway from food during swallowing. We will continue a comparative study of morphology and mechanics of lower airway structures in numerous species, using lung inflations, 3D lung and trachea anatomy from CT scans, and microscopy and composition of alveolae to determine how lungs empty in respiration and collapse at depth. Based on a hyperbaric CT scan, we will create a finite element model of thoracic compression to see how thoracic wall and diaphragm deformation compress the lungs at depth and shift blood volumes between the thorax and the thoracic and cranial retia.   Inner ear structure and hearing. We now know how to image cochlea hair cells, and have made the first spatial frequency map of a whale (beluga) cochlea with the aim of linking damage seen in stranded casualties to specific sound sources. We plan similar work on additional species, including rorquals, whose hearing capacities are unknown. Our research program on whale biomechanics will produce the most comprehensive and quantitative study of swimming, diving and feeding in the great whales, and their anatomical and physiological adaptations specific to these functions.