CONTROL OF FLOW OF FETAL LUNG FLUID AT LARYNGEAL OUTLET
CONTROL OF FLOW OF FETAL LUNG FLUID AT LARYNGEAL OUTLET
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DOI：
10.1016/0034-5687(67)90035-7
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发表时间：
1967-01-01
期刊：
影响因子：
--
通讯作者：
TOWERS, B
中科院分区：
文献类型：
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作者：
ADAMS, FH;DESILETS, DT;TOWERS, B
胎盘循环完整的近足月羔羊通过剖宫产分娩。造影剂注入气管的电影片显示喉出口处存在括约肌机制。括约肌周期性地打开，允许肺液排入鼻腔和咽部，在那里被吞咽。该机制由两个大的杓状软骨组成，它们通过包括甲状软骨和杓间肌的肌肉吊索的收缩而保持在一起并靠在会厌软骨的背面。注入鼻或口中的物质不会进入气管，除非脐带堵塞。切断喉返神经使括约肌的肌肉部分麻痹。该机制可能通过维持腔内正压来帮助肺部生长，并有助于肺部表面活性物质的保留。它也是子宫内粘液和羊水进入未来气道的屏障。
Lambs near term with placental circulations intact were delivered by cesarean section. Cineroentgenograms of contrast material injected into the trachea demonstrated the presence of a sphincter mechanism at the laryngeal outlet. The sphincter opened periodically and allowed the lung fluid to be discharged into the nose and pharynx where it was swallowed. The mechanism consists of two large arytenoid cartilages which are held together and up against the back of the epiglottic cartilage by contraction of a muscular sling comprising thyro-arytenoid and inter-arytenoid muscles. Material injected into the nose or mouth did not enter the trachea except following occlusion of the umbilical cord. Sectioning the recurrent laryngeal nerves paralysed the muscle component of the sphincter. The mechanism probably aids in lung growth by maintaining a positive intraluminal pressure, and assists in the retention of lung surfactant. It also acts as a barrier to the ingress of mucus and amniotic fluid in utero into the future airway.