RESPIRATORY ACTION OF THE INTERCOSTAL MUSCLES

描述：肋间肌扩张胸腔， 呼吸的重要作用。 胸腔是一个复杂的机制， 肋间肌肉的动作和动作的协调， 不太了解。 在拟议的研究中，建模，理论和 实验将结合起来，以确定呼吸作用的 肋间肌 机械优势被定义为 每单位主动肌力的气道压力。 麦克斯韦倒易定理 用于表明机械效益可以通过测量 在放松的胸壁扩张期间的部分肌肉缩短。 在 以前的工作，调查人员已经证明了这一点的有效性 方法，并测量了机械效益的分布和模式， 激活狗胸骨旁区域的内部肋间。 现在将使用该方法来确定呼吸作用， 斜角肌、胸锁乳突肌、肋间外侧肌和骨间内侧肌 狗的肋间肌 将检验以下假设：1） 犬的斜角肌和胸锁乳突肌具有较小的机械优势; 2） 外部肋间肌和骨间肌的力学优势 背腹侧和喙尾侧的内部肋间肌变化 方向，以及在这些肌肉中活动的分布， 呼吸与机械效益的分配相匹配; 3） 胸骨旁和外部肋间骨沿着不同的方向驱动肋骨架 轨迹，以及这两个激活的特定协调 为了驱动肋骨架沿着其松弛， 弹道 机械优势将通过测量肌肉来确定 在放松的胸壁扩张期间缩短。 的分布 自主呼吸期间的肌肉激活将被测量为 最大肌肉激活分数。 最后，该方法将应用于人类。 肌肉定向数据 从尸体上获得的数据和从CT扫描中获得的肋骨位置数据， 两个肺体积下的胸腔将用于计算肌肉缩短 从而获得人体肋间肌的力学优势。

DESCRIPTION: The intercostal muscles expand the rib cage and play an essential role in breathing. The rib cage is a complex mechanism, and the actions and coordination of the actions of the intercostal muscles are poorly understood. In the proposed research, modeling, theory, and experiment will be combined to determine the respiratory action of the intercostal muscles. Mechanical advantage is defined as the change in airway pressure per unit active muscle force. Maxwell's reciprocity theorem is used to show that mechanical advantage can be determined by measuring fractional muscle shortening during expansion of the relaxed chest wall. In previous work, the investigators have demonstrated the validity of this method and measured the distribution of mechanical advantage and pattern of activation of the internal intercostal of the parasternal region of the dog. This method will now be used to determine the respiratory action of the scalenes, sternomastoids, external intercostals, and interosseous internal intercostals of the dog. The following hypotheses will be tested: 1) the scalenes and sternomastoids in the dog have small mechanical advantage; 2) the mechanical advantages of the external intercostals and the interosseous internal intercostals vary in both the dorsoventral and rostrocaudal directions, and the distribution of activity in these muscles during breathing is matched with the distribution of mechanical advantage; and 3) the parasternal and external intercostals drive the rib cage along different trajectories, and a particular coordination of the activation of these two groups is required in order to drive the rib cage along its relaxation trajectory. Mechanical advantage will be determined by measuring muscle shortening during expansion of the relaxed chest wall. The distribution of muscle activation during spontaneous breathing will be measured as a fraction of maximum muscle activation. Finally, the method will be applied to humans. Data on muscle orientation obtained from cadavers and data on rib locations obtained from CT scans of the thorax at two lung volumes will be used to calculate muscle shortening and thereby obtain the mechanical advantages of the human intercostals.