MECHANICS AND CONTROL OF UPPER AIRWAY MUSCLES

上呼吸道间歇性阻塞的临床意义 阻塞性睡眠呼吸暂停综合征导致相当大的发病率： 缺氧、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 差异 对上呼吸道的化学和机械刺激的电反应 和胸部肌肉与 阻塞性睡眠呼吸暂停;拟议的研究将有助于确定 上呼吸道神经激活的机械相关性 肌肉. 在自主呼吸的麻醉犬中， 通过测量上气道肌肉的输出来评估上气道肌肉的输出 肌肉长度变化（使用声测微法）和上气道阻力 在整个呼吸周期中不断地发生，而这些机械事件 将与同时记录的上气道肌肉进行比较 肌电图活动 具体而言，这些研究将（1）定义 上呼吸道肌肉时相性与张力性变化关系 活动（电活动和缩短），以及鼻， 呼吸周期中的咽部和喉部阻力，以及 描述这些关系如何受到化学和反射的影响 刺激呼吸;（2）比较不同的上气道肌肉 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、咽和喉的阻力;（3）确定 上气道正压和负压变化 阻力、静息上气道肌肉长度以及相位和紧张性 上呼吸道肌肉的激活;以及（4）表征 单个上气道肌肉（通过电刺激）影响上气道 气道阻力，不同的上气道肌肉如何共同作用， 增加上呼吸道大小，以及休息位置和长度的变化 影响它们的机械动作和神经活动。 在 此外，从麻醉大鼠获得的分离的上呼吸道肌肉， 狗将在体外进行研究，以评估它们的长度-张力， 力-频率关系及其疲劳特性;以及这些 研究结果将与力产生能力和疲劳进行比较 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.