Boggs D F, Butler P J, Wallace S E
School of Biological Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
J Exp Biol. 1998 Sep;201(Pt 18):2665-8. doi: 10.1242/jeb.201.18.2665.
The air in the respiratory system of diving birds contains a large proportion of the body oxygen stores, but it must be in the lungs for gas exchange with blood to occur. To test the hypothesis that locomotion induces mixing of air sac air with lung air during dives, we measured differential pressures between the interclavicular and posterior thoracic air sacs in five diving tufted ducks Aythya fuligula. The peak differential pressure between posterior thoracic and interclavicular air sacs, 0.49+/-0.13 kPa (mean +/- s.d.), varied substantially during underwater paddling as indicated by gastrocnemius muscle activity. These data support the hypothesis that locomotion, perhaps through associated abdominal muscle activity, intermittently compresses the posterior air sacs more than the anterior ones. The result is differential pressure fluctuations that might induce the movement of air between air sacs and through the lungs during dives.
潜水鸟类呼吸系统中的空气含有很大比例的机体氧气储备，但这些空气必须位于肺部才能与血液进行气体交换。为了验证潜水过程中运动是否会促使气囊空气与肺部空气混合这一假设，我们测量了五只斑脸海番鸭（Aythya fuligula）锁骨间气囊与胸后气囊之间的压差。胸后气囊与锁骨间气囊之间的最大压差为0.49±0.13千帕（平均值±标准差），在水下划水过程中，随着腓肠肌活动的变化，该压差有显著波动。这些数据支持了以下假设：运动，可能是通过相关的腹部肌肉活动，间歇性地对后气囊产生比对前气囊更大的压缩。其结果是压差波动，这可能会在潜水过程中促使空气在气囊之间流动并通过肺部。
