RESPIRATORY ACTION OF THE INTERCOSTAL MUSCLES

肋间肌肉驱动肋骨笼的扩张和收缩 在呼吸过程中。肋间肌肉的作用已被研究过。 主要通过研究它们对肋骨移位的影响，但它们对 肺容量扩张仍然知之甚少。在我们之前的工作中，我们 将建模、理论和实验相结合，建立了一种方法 评价肋间肌的机械优势。机械式 优势被定义为单位力量的呼吸道压力的变化 由活跃的肌肉施加的，机械优势被证明是相等的 被动胸肌单位扩容时的肌肉缩短分数 墙。我们计算了肋间肌肉的力学优势。 并测试了我们对狗的最大呼吸效应的预测 整个吸气肌群。计算揭示了新的 关于吸气性肋间呼吸作用的信息 肌肉。计算的肋间内侧结构的机械优势 在胸骨旁区域(PA)显示每个间隙内的梯度 机械优势随着与胸骨的距离而降低， 空间之间的坡度，机械优势在第三层更大 而不是在第六个空间。在机械优势方面的梯度 外部肋间也预测有机械优势。 背侧最大，向腹侧逐渐减少 区域。我们假设肌肉激活的分布 在自主呼吸过程中可能遵循机械的分布 优势。在拟议的研究中，我们将测试计算值 通过测量PA和EI的缩短来获得机械优势 空间内和空间间位置的函数。我们会 测量激活的分布，作为最大值的分数 PA和EI的激活，以检验肌肉具有最大 机械优势在呼吸过程中更为活跃。

The intercostal muscles drive expansion and contraction of the rib cage during respiration. The action of the intercostal muscles has been studied primarily by studying their effect on rib displacement, but their effect on lung volume expansion is still poorly understood. In our previous work, we combined modeling, theory, and experiment to establish a method for evaluating the mechanical advantage of the intercostal muscles. Mechanical advantage was defined as the change in airway pressure per unit force exerted by an active muscle, and mechanical advantage was shown to equal fractional muscle shortening per unit volume expansion of the passive chest wall. We calculated the mechanical advantages of the intercostal muscles of the dog and tested our prediction of the maximum respiratory effect of entire inspiratory muscle groups. The calculations revealed new information about the respiratory action of the inspiratory intercostal muscles. The calculated mechanical advantage of the internal intercostals in the parasternal region (PA) showed a gradient within each interspace with mechanical advantage decreasing with distance from the sternum and a gradient between interspaces with mechanical advantage greater in the third than in the sixth interspace. Gradients in mechanical advantage of the external intercostals were also predicted with mechanical advantage greatest in the dorsal region and decreasing gradually toward the ventral region. We hypothesized that the distribution of the muscle activation during spontaneous breathing might follow the distribution of mechanical advantage. In the proposed research, we will test the calculated values of mechanical advantage by measuring the shortening of the PA and EI as a function of position within interspaces and across interspaces. We will measure the distribution of activation, as a fraction of maximal activation, of PA and EI to test the hypothesis that muscles with greatest mechanical advantage are more active during breathing.