EFFECTS OF CRICOTHYROID MUSCLE-CONTRACTION ON UPPER AIRWAY FLOW DYNAMICS IN DOGS
EFFECTS OF CRICOTHYROID MUSCLE-CONTRACTION ON UPPER AIRWAY FLOW DYNAMICS IN DOGS
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DOI：
10.1152/jappl.1992.72.6.2329
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发表时间：
1992-06-01
影响因子：
3.3
通讯作者：
ENGEL, LA
中科院分区：
文献类型：
--
作者：
AMIS, TC;BRANCATISANO, A;ENGEL, LA
我们研究了环甲肌（CT）收缩对8只俯卧张口麻醉犬上气道血流动力学的影响。动物通过气管切开术机械通气，同时恒定气流（Vuaw）通过孤立的上呼吸道。鼻气流（Vn）监测使用鼻罩和肺记录仪。电刺激喉上神经外支引起双侧CT收缩。在吸气方向Vuaw为100 ~ 443 ml/s的CT收缩期间，上呼吸道总阻力（Ruaw）下降49.1 +/- 5.4% (SE)，声门上阻力下降63.6 +/- 3.6%；与此同时，越南股市下跌了55.3 +/- 3.8%，越南股市上涨了7.2 +/- 1.7%。当Vuaw在呼气方向时也得到类似的结果。在3只CT与甲状腺或环状软骨的连接被切断的狗中，喉上神经刺激对Ruaw没有系统性影响。由于CT收缩期间的视觉评估一致显示梨状窝的扩张，我们认为CT收缩与咽部扩张有关，这在张嘴的狗（有重叠的软腭和会囊）中重新分配流到口腔途径，使Ruaw净减少。因此，CT可作为咽扩张器发挥呼吸作用。
We studied the effects of cricothyroid muscle (CT) contraction on upper airway flow dynamics in eight prone open-mouth anesthetized dogs. Animals were mechanically ventilated via a tracheostomy while a constant airflow (Vuaw) passed through the isolated upper airway. Nasal airflow (Vn) was monitored using a nasal mask and pneumotachograph. Bilateral CT contraction was induced by electrical stimulation of the external branches of the superior laryngeal nerves. During CT contraction with Vuaw of 100-443 ml/s in the inspiratory direction, total upper airway resistance (Ruaw) fell by 49.1 +/- 5.4% (SE) while supra-glottic resistance fell by 63.6 +/- 3.6%; simultaneously Vn fell by 55.3 +/- 3.8% and Vuaw increased by 7.2 +/- 1.7%. Similar results were obtained when Vuaw was in the expiratory direction. In three dogs in which the attachments of the CT to either the thyroid or cricoid cartilage were severed, superior laryngeal nerve stimulation had no systematic effect on Ruaw. Because visual assessment during CT contraction consistently revealed dilation of the piriform recesses, we suggest that CT contraction is associated with pharyngeal dilation, which in open-mouth dogs (with overlapping soft palate and epiglottis) redistributes flow to the oral route with a net reduction in Ruaw. Thus the CT may have a respiratory role as a pharyngeal dilator.