摘要
收集3～10个月胎儿90例,大体观测其动脉导管及相关结构,其中48例用组织学方法观察动脉导管组织结构的演变,探讨其闭锁机理。动脉导管属肌性动脉,胎儿第7月末,导管组织结构变化显著,导管迅速增长、管腔迅速扩大的同时,内膜增厚,内膜中的内弹性膜出现断裂并逐渐加剧,有些平滑肌纤维从断裂的内弹性膜间隙突入,与增厚的内膜共同形成内膜垫,这个时期是动脉导管组织结构演变的关键时期。胎儿第7月末之后,肺和肺循环发育完善,但左右肺动脉仍处于“门虽设而常关”状态,肺动脉干血流挤入较其小得多的动脉导管,使后者受局部血流高压影响,达可能就是动脉导管发生组织学演变的重要内因。胎儿娩出后,这些组织学变化成为导管闭锁的基础。
In this study, 90 fetuses aged from 3～10 months were collected, 48 of 90 ductus arteriosi were studied with histological method in order to observe the changes in the different fetal stages and to approach its closing mechanism. The gross morphology of the 90 ductus arteriosi and their abjacent portions were also observed. Ductus arteriosus belong to the muscular type artery. It was found that the histological structure of the ductus arteriosus after the 7th month was particulary different from that before the 7th month, the beginning of the perinatal period is the critical period of the histological changes of the ductus arteriosus, since the beginning of the perinatal period, the duct had grown rapidly, the internal elastic membrane was fragmented or split, the smooth muscular fibers of the inner layer in the tunica media remarkbly thickened and was disarranged, some oblique and spokelike smooth muscular fibers protruded into the intima through the gaps between the fragmental internal elastic membranes and formed typical intima cushions with the thickened tunica intima. From the beginning of the perinatal period, the lungs and the vessels of pulmonary circulation had been well developed, but the right and left pulmonary arteries were in the state of 'the door being placed but usually closed'. Blood of the pulmonary trunk flowed into the much smaller ductus arteriosus, hence the ductus arteriosus was an artery affected by local hyper-pressure, its histological changes were similar to the degeneration of the muscular artery affected by hypertension disease, but it had no lipid deposit. This local hyper-pressure may be the intrinstc cause of the histological changes of the ductus arteriosus. These histological changes were the morphological foundation of the functional closure and anatomical closure of the ductus arteriosus after birth.
出处
《解剖学报》
CAS
CSCD
北大核心
1992年第3期240-243,共4页
Acta Anatomica Sinica
关键词
动脉导管
组织学
闭锁机理
Ductus arteriosus
Histology
Closing mechanism
