Banzett R B, Nations C S, Wang N, Butler J P, Lehr J L
Respiratory Biology Program, Harvard School of Public Health, Boston, MA 02115.
Respir Physiol. 1992 Jul;89(1):27-36. doi: 10.1016/0034-5687(92)90068-8.
The pectoral muscles in birds comprise up to a third of the body weight and provide the principal drive to the wing. Their attachment to the sternum suggests that they could compress the thorax and assist ventilation during flight. Most, but not all, birds have an integer ratio relationship between wingbeat and breathing frequency, but no measurements of the respiratory flow associated with the act of wingbeat are available. We recorded respiratory flow and wing timing in three starlings that flew at 22 knots (11 m.s-1) for up to 5 min in a wind tunnel. Triggering on wingbeat, we ensemble averaged flow records for many wingbeats in each flight. Because wingbeats occurred throughout the respiratory cycle, breathing flow tended to average to zero, and a small flow event related to wingbeat emerged. The volume change associated with wingbeat ranged from 3 to 11% of tidal volume, and this is probably an overestimate. We conclude that wingbeat and breathing in starlings are essentially mechanically independent, despite the direct attachment of the locomotor muscles to the thorax.
鸟类的胸肌重量可达体重的三分之一，为翅膀提供主要驱动力。它们与胸骨的附着表明，在飞行过程中胸肌可能会压缩胸腔并辅助呼吸。大多数（但并非所有）鸟类的振翅频率与呼吸频率之间存在整数比关系，但目前尚无与振翅动作相关的呼吸流量测量数据。我们在风洞中记录了三只以22节（11米/秒）的速度飞行长达5分钟的椋鸟的呼吸流量和振翅时间。以振翅为触发信号，我们对每次飞行中多个振翅周期的流量记录进行了总体平均。由于振翅发生在整个呼吸周期中，呼吸流量趋于平均为零，与振翅相关的小流量事件显现出来。与振翅相关的体积变化占潮气量的3%至11%，这可能是高估了。我们得出结论，尽管运动肌肉直接附着于胸腔，但椋鸟的振翅和呼吸在本质上是机械独立的。
