TRANSMURAL ORGANIZATION OF THE ARTERIAL MEDIA - THE LAMELLAR UNIT REVISITED
TRANSMURAL ORGANIZATION OF THE ARTERIAL MEDIA - THE LAMELLAR UNIT REVISITED
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DOI：
10.1161/01.atv.5.1.19
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发表时间：
1985-01-01
期刊：
影响因子：
--
通讯作者：
GLAGOV, S
中科院分区：
文献类型：
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作者：
CLARK, JM;GLAGOV, S
当扩张主动脉正交透壁骨折表面的扫描电子显微照片与相应的半薄光学显微镜和超薄透射电子显微镜切片上的外观进行比较时，内侧板层单元可以分解为平行于切片切线的重叠、肌弹性束的复合材料。每个束由一组共同定向的细长平滑肌细胞和一系列分支的、类似定向的弹性纤维组成。在主动脉直段的纵向切片上，束表现为紧密堆积的、横向横切的平滑肌细胞群，其内部由类似横切的弹性纤维形成。在横向切片上，束表现为层状细胞带内的细胞群，每个细胞的腔内和腔外两侧均由直弹性纤维支撑。在生长过程中，束变得越来越明显，因为已经存在的同心细胞层内的共同定向的细胞群通过扩大的弹性纤维而被划分开。与直接细胞周基质的交错原纤维不同，波状胶原纤维束主要插入到面对的弹性蛋白系统与细胞层之间的纤维区域之间。发育良好的主动脉中层横切面的细胞和基质纤维呈放射状透壁分布，包括弹性蛋白-细胞-弹性蛋白、胶原束、弹性蛋白-细胞-弹性蛋白、胶原束等。主动脉中层也由肌弹性束组成，但其包围的弹性纤维系统不如主动脉突出。在主动脉和动脉的直段中，束在任何给定的透壁水平上尺寸均一，并且主要沿周向定向。在弯曲处和分支处，分束较小且尺寸和方向不太均匀。关于血管壁曲率的变化，束的排列通常沿着假定的合成拉应力的方向。内侧组织的这些亚单位显然对应于拉应力的分布和大小。
When scanning electron micrographs of orthogonadal transmural fracture surfaces of distended aortas were compared with appearances on corresponding semithin light microscopic and ultrathin transmission electron microscopic sections, medial lamellar units could be resolved into composites of overlapping, musculo-elastic fascicles lying parallel to tangential lines of section. Each fascicle consisted of a group of commonly oriented, elongated smooth muscle cells and an encompassing array of branching, similarly oriented elastic fibers. On longitudinal sections of straight segments of the aorta, fascicles appeared as closely packed, transversely transected smooth muscle cell groups within compartments formed by similarly transected elastic fibers. On transverse sections, fascicles appeared as groups of cells within cell strips of layers, each of which was bracketed on both its luminal and abluminal sides by straight elastic fibers. Fascicles were increasingly evident during growth as commonly oriented groups of cells within the already present concentric cell layers became demarcated by enlarging elastic fibers. Wavy collagen fiber bundles, distinct from the interlaced fibrils of the immediate pericellular matrix, were interposed mainly between the facing elastin systems with the fibrous regions between cell layers. The radial transmural disposition of cells and matrix fibers on transverse sections of the media in well developed aortas proved to be elastin-cells-elastin, collagen bundles, elastin-cells-elastin, collagen bundles, etc. Medias of major branch arteries were also composed of musculo-elastic fascicles, but their encompasing elastic fiber systems were less prominent than in the aorta. In straight segments of aortas and arteries, fascicles were uniform in size at any given transmural level and oriented mainly circumferentially. At bends and branch plots fascicles were smaller and less uniform in size and orientation. In relation to changes in vessel wall curvature, alignment of the fascicles was usually in the direction of presumed resultant tensile stress. These subunits of medial organization apparently correspond to the distribution and magnitude of tensile stresses.