The metabolic power requirements of flight and estimations of flight muscle efficiency in the cockatiel (Nymphicus hollandicus)
The metabolic power requirements of flight and estimations of flight muscle efficiency in the cockatiel (Nymphicus hollandicus)
复制标题
DOI：
10.1242/jeb.035717
复制
发表时间：
2010-08-15
影响因子：
2.8
通讯作者：
Askew, Graham N.
中科院分区：
文献类型：
--
作者：
Morris, Charlotte R.;Nelson, Frank E.;Askew, Graham N.
很少有人知道如何在体内肌肉的效率，即机械和代谢功率的比例，是由运动任务的变化的影响。确定体内肌肉效率的主要问题之一是通常用于产生机械动力的大量肌肉。动物飞行提供了一个确定肌肉效率的独特模型，因为只有一块肌肉，胸肌，产生几乎所有飞行所需的机械动力。为了估计体内飞行肌肉的效率，我们测量了代谢成本的飞行在一个范围内的飞行速度（6- 13米秒（-1））使用蒙面呼吸法在凤头鹦鹉（Nymphicus hollandicus），并将其与测量的机械功率在同一风洞中确定。与机械功率-速度关系的测量结果相似，代谢功率-速度关系呈U形，在10 m s（-1）时最小。虽然机械和代谢功率-速度关系具有相似的最小功率速度，但代谢功率要求不是在飞行速度范围内的机械功率要求的简单倍数。胸肌的效率（估计从机械和代谢功率，基础代谢和假设值的“姿势成本”的飞行）增加与飞行速度和范围从6.9%到11.2%。然而，之前对飞行姿势成本的估计可能太低，而胸大肌的效率更高。
Little is known about how in vivo muscle efficiency, that is the ratio of mechanical and metabolic power, is affected by changes in locomotory tasks. One of the main problems with determining in vivo muscle efficiency is the large number of muscles generally used to produce mechanical power. Animal flight provides a unique model for determining muscle efficiency because only one muscle, the pectoralis muscle, produces nearly all of the mechanical power required for flight. In order to estimate in vivo flight muscle efficiency, we measured the metabolic cost of flight across a range of flight speeds (6-13m s(-1)) using masked respirometry in the cockatiel (Nymphicus hollandicus) and compared it with measurements of mechanical power determined in the same wind tunnel. Similar to measurements of the mechanical power-speed relationship, the metabolic power-speed relationship had a U-shape, with a minimum at 10 m s(-1). Although the mechanical and metabolic power-speed relationships had similar minimum power speeds, the metabolic power requirements are not a simple multiple of the mechanical power requirements across a range of flight speeds. The pectoralis muscle efficiency (estimated from mechanical and metabolic power, basal metabolism and an assumed value for the 'postural costs' of flight) increased with flight speed and ranged from 6.9% to 11.2%. However, it is probable that previous estimates of the postural costs of flight have been too low and that the pectoralis muscle efficiency is higher.