MECHANICS AND CONTROL OF UPPER AIRWAY MUSCLES

慢性阻塞性肺疾病患者上呼吸道间歇性闭塞 阻塞性睡眠呼吸暂停综合征导致相当大的发病率： 低氧、高碳酸血症、心律失常、肺心病、红细胞增多症和 各种神经精神症状。中美之间的差异 上呼吸道对化学和机械刺激的电反应 而胸肌被认为参与了胸腺瘤的发病 阻塞性睡眠呼吸暂停；拟议的研究将有助于定义 上呼吸道神经活动的力学相关因素 肌肉。在自主呼吸的麻醉犬中，机械的 上呼吸道肌肉的输出将通过测量上呼吸道来评估 肌肉长度变化(使用声学显微镜)和上呼吸道阻力 在整个呼吸周期中，这些机械事件 将与同时记录的上呼吸道肌肉进行比较 肌电活动。具体地说，这些研究将(1)界定 上呼吸道肌肉的时相变化与紧张性变化的关系 活动(电活动和缩短)，以及鼻部的变化， 呼吸周期中的咽喉阻力，以及 描绘出这些关系是如何受到化学和反射性影响的 刺激呼吸；(2)比较不同的上呼吸道肌肉 对化学感受器的刺激作出电和机械反应 机械感受器，并评估这些刺激对上呼吸道的影响 鼻部、咽部和喉部的阻力；(3)确定 上呼吸道正负压变化对上呼吸道的影响 阻力、静息上呼吸道肌肉长度、气相和强直性 上呼吸道肌肉的激活；和(4)表征如何激活 单个上呼吸道肌肉(通过电刺激)影响上呼吸道 呼吸道阻力，即不同的上呼吸道肌肉如何共同作用于 增加上呼吸道的大小，以及休息位置和长度的变化 这些肌肉中的一部分会影响它们的机械动作和神经激活。在……里面 此外，从麻醉大鼠获得的分离的上呼吸道肌肉和 狗将在体外进行研究，以评估它们的长度-张力和 力-频率关系及其疲劳特性；以及这些 研究结果将与力量产生能力和疲劳程度进行比较。 隔膜的特性。

The intermittent occlusion of the upper airway in patients with the obstructive sleep apnea syndrome results in considerable morbidity: hypoxia, hypercapnia, cardiac arrhythmias, cor pulmonale, polycythemia, and a variety of neuropsychiatric manifestations. Differences in the electrical responses to chemical and mechanical stimuli of the upper airway and thoracic muscles have been implicated in the pathogenesis of obstructive sleep apneas; the proposed studies will help define the mechanical correlates of the neural activation of the upper airway muscles. In spontaneously breathing anesthetized dogs, the mechanical output of upper airway muscles will be assessed by measuring upper airway muscle length changes (using sonomicrometry) and upper airway resistance continuously throughout the respiratory cycle, and these mechanical events will be compared to simultaneously recorded upper airway muscle electromyographic activity. Specifically, these studies will (1) define the relationship between phasic and tonic changes in upper airway muscle activity (electrical activity and shortening), and changes in nasal, pharyngeal and laryngeal resistance during the respiratory cycle, and delineate how these relationships are affected by chemically and reflexly stimulated breathing; (2) compare how different upper airway muscles respond electrically and mechanically to stimulation of chemoreceptors and mechanoreceptors, and assess the effects of these stimuli on upper airway resistance at the nose, pharynx and larynx; (3) define the effects of positive and negative upper airway pressure changes on upper airway resistance, resting upper airway muscle lengths, and the phasic and tonic activation of upper airway muscles; and (4) characterize how activation of single upper airway muscles (by electrical stimulation) affects upper airway resistance, how the different upper airway muscles act together to increase upper airway size, and how changes in resting position and length of these muscles affect their mechanical actions and neural activation. In addition, isolated upper airway muscles obtained from anesthetized rats and dogs will be studied in vitro to assess their length-tension and force-frequency relationships, and their fatigue characteristics; and these findings will be compared to the force generating capacity and fatigue characteristics of the diaphragm.