Structural basis for alterations in upper airway collapsibility.

To determine the structural basis for alterations in upper airway (UA) collapsibility, the pharyngeal critical pressure (Pcrit) was measured in an isolated feline upper airway preparation. The effect of airway elongation and dilation was explored by displacing the trachea caudally and the tongue anteriorly, respectively. With caudal-tracheal displacement, Pcrit fell progressively, a result that can be attributed to increased tension within the pharyngeal mucosa. In contrast, anterior-tongue displacement decreased Pcrit when the trachea had been caudally displaced but not with the trachea in the neutral position. These findings suggest that longitudinal tension within the airway mucosa modulates both Pcrit and the response in Pcrit to dilating forces. A mechanical model to account for these findings is discussed.

为确定上气道（UA）可塌陷性改变的结构基础，在一个离体的猫上气道标本中测量了咽部临界压力（Pcrit）。分别通过将气管向尾侧移位和将舌向前移位来探究气道伸长和扩张的影响。随着气管向尾侧移位，Pcrit逐渐下降，这一结果可归因于咽部黏膜内张力增加。相反，当气管已向尾侧移位时，舌向前移位会使Pcrit降低，但在气管处于中立位置时则不会。这些发现表明，气道黏膜内的纵向张力既调节Pcrit，也调节Pcrit对扩张力的反应。文中还讨论了一个用于解释这些发现的力学模型。