Reed W R, Roberts J L, Thach B T
J Appl Physiol (1985). 1985 Feb;58(2):635-44. doi: 10.1152/jappl.1985.58.2.635.
To study factors influencing patency and configuration of the upper airway, we studied 11 infant cadavers using endoscopy and photography. In most cases, studies were performed shortly after death. The naso-, oro-, and hypopharynx and the larynx were studied. The upper airway was sealed at the nose and mouth so that transmural airway pressure could be raised or lowered. As pressure was lowered airway closure was seen in each of the four regions studied. With respect to closing pressure, the oropharynx was the most compliant region and the larynx the least compliant. In the naso-, oro-, and hypopharynx, lowering the transmural pressure was associated with inward movement of the anterior, posterior, and lateral airway walls. In the larynx, closure occurred by vocal cord opposition in the midline. Tension applied to the genioglossus and geniohyoid tongue muscles had an effect opposite to that of airway suction, causing a more or less symmetrical dilation of the naso- and oropharynx. When the airway was closed, additional tension was needed to produce airway reopening, suggesting that adhesion forces act to maintain airway closure. Neck flexion caused pharyngeal closure, and neck extension caused pharyngeal dilation. Secretions adherent to the walls of the airway visibly narrowed its lumen. The relevance of these findings for the obstructive sleep apnea and laryngomalacia syndromes is discussed.
为研究影响上呼吸道通畅性及形态的因素，我们使用内窥镜检查和摄影技术对11具婴儿尸体进行了研究。在大多数情况下，研究在死亡后不久进行。对鼻、口、下咽及喉部进行了研究。对上呼吸道在鼻和口处进行密封，以便能够升高或降低跨壁气道压力。随着压力降低，在所研究的四个区域均可见气道闭合。关于闭合压力，口咽部是最顺应性的区域，而喉部是顺应性最低的区域。在鼻、口、下咽，降低跨壁压力与气道前壁、后壁及侧壁的向内移动有关。在喉部，闭合是通过声带在中线处相对而发生的。对颏舌肌和颏舌骨肌施加张力产生的效果与气道抽吸相反，导致鼻和口咽部或多或少对称的扩张。当气道闭合时，需要额外的张力才能使气道重新开放，这表明粘附力起到维持气道闭合的作用。颈部屈曲导致咽部闭合，颈部伸展导致咽部扩张。附着在气道壁上的分泌物明显使管腔变窄。讨论了这些发现与阻塞性睡眠呼吸暂停和喉软化综合征的相关性。
