Function of the Axial Musculoskeletal System in Locomotion and Ventilation

剧烈运动需要加快新陈代谢。因此，对于维持快速运动的动物来说，它必须在奔跑时呼吸。尽管人类在运动时呼吸是理所当然的，但越来越多的证据表明，同时跑步和呼吸的能力是陆生脊椎动物的衍生条件。对鱼类和两栖动物的分析清楚地表明，腹部和胸部肌肉的原始功能是运动而不是肺通气。这一点的重要性在蜥蜴身上表现得很明显，它们产生通风的肌肉在运动中也有作用。在这些蜥蜴中，轴向肌肉的运动功能比它们的呼吸功能更重要。因此，在某些物种中，躯干肌肉的运动动作干扰呼吸的程度如此之大，以至于肺通气量和耗氧量都随着速度的增加而下降。同样，在狗身上，轴向肌的运动功能似乎比这些肌肉的通气功能更重要。当小跑的狗将呼吸与运动周期分开时，除了一两个躯干肌肉外，其他所有肌肉的活动都锁定在步幅周期上。这表明，四足动物要么无法同时奔跑和呼吸，要么它们的呼吸必须以某种方式与运动相结合。本研究旨在通过研究轴向肌肉-骨骼系统在跑步和呼吸中的作用，增加我们对运动和呼吸系统之间机械联系的理解。它有两个目标。首先，Carrier博士将使用肌电图和运动力的操作来测试蜥蜴和哺乳动物轴向肌运动功能的特定假设。其次，通过比较呼吸与运动周期耦合与不耦合时的肌肉活动强度，PI将确定运动-呼吸耦合是否会减少哺乳动物跑步与呼吸之间的冲突。这项研究将有助于我们理解在面对运动产生的冲突需求时维持氧级联的方式；这将有助于澄清蜥蜴和哺乳动物之间的差异，这可能有助于解释奔跑的蜥蜴依赖于无氧代谢以及哺乳动物维持剧烈有氧运动的能力。

9807534 Carrier Vigorous activity requires elevated rates of metabolism. Thus, for an animal to sustain rapid locomotion, it must breathe as it runs. Although humans take breathing during locomotion for granted, there is increasing evidence that the ability to run and breathe at the same time is a derived condition among terrestrial vertebrates. analysis of fishes and amphibians clearly shows that the original function of the muscles of the abdomen and thorax was locomotion rather than lung ventilation. The significance of this is apparent in lizards in which the muscles that produce ventilation also have a role in locomotion. In these lizards, the locomotor function of the axial muscles predominates over their ventilatory function. Consequently, in some species, the locomotor actions of the trunk muscles interfere with breathing to such an extent that and both lung ventilation and oxygen consumption decline as speed increases. Similarly, in dogs, the locomotor function of the axial muscles appears to be dominate over the ventilatory function of these muscles. When trotting dogs uncouple their breathing from the locomotor cycle, activity of all but one or two of the trunk muscles stays locked to the stride cycle. This suggests that tetrapods will either be unable to run and breathe at the same time, or their ventilation must in some way be integrated with their locomotion. The research described in this proposal is intended to increase our understanding of the mechanical linkage between the locomotor and ventilatory systems by investigating the role the axial muscle-skeletal system plays in running and breathing. It has two goals. First Dr. Carrier will use electromyography and manipulation of locomotor forces to test specific hypotheses of locomotor function for the axial muscles in both lizards and mammals. Second, by comparing the intensity of muscle activity when ventilation is coupled versus not coupled to the locomotor cycle, the PI will determine whether locomotor-venti latory coupling decreases the conflict between running and breathing in mammals. This study will contribute to our understanding of the ways in which the oxygen cascade is maintained in the face of conflicting demands resulting from locomotion; and it will help clarify differences between lizards and mammals which may help explain the reliance of running lizards on anaerobic metabolism and the ability of mammals to sustain vigorous locomotion aerobically.