人窦房结和房室结微血管的扫描电镜观察

SCANNING ELECTRON MICROSCOPIC OBSERVATION ON THE MICROVESSELS IN THE HUMAN SINOATRIAL NODE AND ATRIOVENTRICULAR NODE

本文用4例新鲜婴儿尸体,采用血管铸型扫描电镜法,观察人窦房结、房室结微血管的立体构筑。结果表明,窦房结的血管床是由微血管网构筑成一椭圆形网状结构,中央动脉贯穿于结的长轴,由此动脉向周围发出分支,逐级分为许多微动脉和毛细血管前微动脉,最后在结的浅部分成毛细血管网。毛细血管后微静脉的收集范围,则显示出按区收集的特点。而房室结微血管构型是一扁圆形的微血管网,结的浅部为一薄层比较细密的毛细血管网。透过网眼,可见有粗大的、彼此吻合的窦状静脉丛。房室结动脉由结一侧进入结内,向周围逐级分支,形成毛细血管前微动脉,穿行于静脉丛之间,在结的浅部连于毛细血管网。毛细血管后微静脉的始端有环形缩窄,为平滑肌压痕。

Four fresh corpses of infant are used in this research. Three-dimensional microvasculatures of the sinoatrial node and atrioventricular node were studied by means of the observation of vascular casts with SEM. The results showed that the vascular bed of the sinoatrial node was consisted of the microvascular networks. It was oval in shape. The central artery penetrated this node, through its longitudinal axis and divided progressively into arterioles and precapillary arterioles and finally, they branched into capillary networks at the superficial part of the node. The postcapillary venules were characterized by draining blood in accordance with area. The microvascular construction of atrioventricular node was an oblate microvascular network in shape. There was a layer of delicate capillary networks at its superficial part. In the depth of the capillary networks, the venous plexus which was thick and sinusoidal in shape was observed through the meshes. The artery of atrioventricular node entered the node from one side of it. In the node, the artery ramified by degrees to periphery into precapillary arterioles, which penetrated venous plexus and connected with capillary networks in the superficial part of the node. There were evidently narrow rings, whick were impression of the muscle sphincters at the origin of thep ostcapillary venules.