胎儿侧脑室脉络丛微血管的形态学特点

Morphological Features of Choroid Plexus Microvessels in Fetal Lateral Ventricles

光镜和电镜观察43例胎儿侧脑室脉络丛的微血管。微血管内径大部分在<20μm,内径大小与胎龄无关;单位面积微血管数随胎儿发育而增多。微血管内皮细胞内可见到单个线粒体分别被粗面内质网包绕。在胎龄>24周的标本,见到内皮细胞有隔膜的孔。作者认为形成脑脊液、转运大分子物质主要依靠内皮细胞的胞饮作用。

The microvessels within the lateral ventricular choroid plexuses of the brains of 43 normal fetuses were observed with electron and lightmicroscopy.These microvessels only consisted of endothelial cells. Their internal diameter was less than 20μm.There was no relationship between the size of their internal diameter and the fetal age.But the more the quantity of these microvessels in unit area was,the older the fetus was.The types and numbers of cell organelles present in endothelia made clear no difference from 10 to 38 weeks' fetal age.Rare endothelial pores were not observed until after age of 24 weeks.Some- times mitochodria were surrounded by rough endoplasmic retieula in endothelia.For these reasons,it is reasonable to expect that all the microvessels whose diameter was less than 20μm had similar functions due to same structure.That they filter the blood fluid to form cerebrospinal fluid mainly depends on the pinocytosis of the endothelial cell.