葡萄膜血管铸型的扫描电镜观察

OBSERVATION ON VASCULAR CASTS OF UVEA NEWBORNS BY SCANNING ELECTRON MICROSCOPY

本文用死后2~4小时的5具新生儿尸体,以ABS丁酮溶液经颈总动脉灌注后,剥下葡萄膜,在40%KOH液中腐蚀4~5天,把所得到的血管腐蚀铸型,在扫描电镜下进行观察。可见脉络膜的血管由大血管层,小血管层和毛细血管层组成。脉络膜的毛细血管层是由许多脉络膜毛细血管小叶组成的。小叶的中央是毛细血管前小动脉,毛细血管呈放射状离开小动脉,与邻近小叶互相吻合,形成连续单层的互相吻合的毛细血管网。毛细血管小叶由斜行或垂直于毛细血管层的毛细血管后小静脉引流。脉络膜毛细血管小叶呈多边形的几何图形。脉络膜的毛细血管突然终止于视神经乳头周围,不参与视神经乳头的血液供应。睫状体和虹膜的血管来自虹膜动脉大环,每个睫状突由一条小动脉供应,形成睫状突的毛细血管丛,它由小静脉引流。睫状突主要由血管构成。

Ten fresh eye balls removed from five newborn cadavers were studied.About2-4 hrs after death,cadavers were injected through both common carotid arteries withABS at a constant pressure between 120~150 mmHg.ABS-injected eyes were enucleatedand were cut into halves through equator or meridian.The specimens were digestedin 40%KOH.The corrosion-cast models of blood vessels in uvea were observed underthe SEM.The chief results of observation were as follows:Within the choroid,the blood vessels lie in stratified layers.The large vesselsare located in the outermost layer,next to this layer are smaller vessels.The innermostlayer consists of a continuous single layer of capillaries.The choriocapillaries end around the optic disc.This finding indicates that thechoriocapillaries are not directly involved in the disc circulation.Each short posterior ciliary artery supplied a segment of the choriocapillaries,with some capillary anastomosis between segments,so that the choriocapillaries werearranged in one plane as a single continuous layer of capillaries forming a network.The network of the choriocapillaries consisted of lobules of choriocapillaries.The precapillary arteriole lie in its center.In each lobule meshed capillaries appearedto radiate from a central focus.The postcapillary venule lay on the periphery of thelobule.The lobules varied in their geometric configuration,forming irregularlytriangular to hexagonal shapes.The average size of a lobules of newborn’s chorioca-pillaries was 230/420μto 460/520μ.The diameter of the choriocapillary varies between8μand 20μ.The blood vessels of the ciliary body and iris divide from large circular arteryof iris and long posterior ciliary arteries.Each ciliary process contained a small arterywhich randomly branched to form a capillary network.It is drained by venule.