用注射复型SEM方法研究足月胎儿小肠粘膜的微循环

MICROCIRCUIATION OF THE SMALL INTESTINE MUCOSA OF A MATURE FETUS AS STUDIED BY THE INJECTION REPLICA SCANNING ELECTRON MICROSCOPE METHOD

本文用注射甲基丙烯酸甲酯复型扫描电镜方法,研究了足月胎儿小肠粘膜血管的立体构筑形象。绒毛毛细血管网的特征为管腔大部分呈窦状,其间夹杂有直形毛细血管;在十二指肠乳头处,胆总管壶腹口周围及壶腹粘膜的毛细血管多呈丛状,未见窦状毛细血管。绒毛的毛细血管网接受来自三方面的动脉血,即通过来自粘膜下动脉的微动脉,从绒毛顶部、基底部和腺丛的交通支,向绒毛毛细血管网供血。后者构成小肠绒毛的“门脉系统”。微动脉在绒毛顶部与微静脉有交通支,构成动静脉吻合。微静脉从顶部到基底部贯穿整个绒毛,沿途自绒毛毛细血管网及腺丛接受属支,最终注入粘膜下静脉,与Mall的典型的“喷泉型”概念并不完全一致。

Three dimensional architecture in the vascular bed of the small intestine mucosa in a mature fetus was studied by the injection replica scanning electron microscope method.This vascular architecture consists of arterioles,venules,capillary network and cryptal plexus.It was observed that the capillary network was mostly sinusoid and partly straight.It is suggested that the capillary network of the villus receives arterial blood from three aspects.1.The arterioles extending from the base to the tip of the villus break up into a capillary network.2.The arterioles at the base of the villus connect with the capillary network.3.The cryptal plexus and the capillary network of the villus communicate with each other.Therefore,the capillary network of the villus is supplied by the cryptal plexus via this communication.The third pattern is the so-called portal system of the small intestine villus.At the tip of the villus,arterioles send out one branch to form an arteriovenous anastomosis with the vein.The venous drainage is conducted by a venule extending from the tip to the base.It receives branches along its course and finally converges into the submucosal veins.Our findings indicated that the capillary networks of the small intestine villus of the mature fetus were different from the typical"fountain"concept supported by Mall(1887).