摘要
本文用光镜、透射和扫描电镜,观察了30例与带瓣静脉段移植有关的肱、股、大隐静脉的瓣膜结构。在光镜和透射电镜下,3种瓣膜的结构基本一致。在两层内皮间有3种机能层;内皮下各有疏松层;细波纹状的弹性纤维层主要位于疏松层内面;弹性纤维层之间为呈环、纵、斜方向的胶原纤维层,胶原纤维层中还有散在的弹性纤维。静脉壁内的平滑肌经瓣膜附着缘延伸入瓣叶内。弹性纤维、平滑肌、胶原纤维在瓣膜承受机械重力和被动开闭机制中起重要作用,基于平滑肌存在于瓣叶内的事实,推测瓣膜本身具有内在的动力机制。透射和扫描电镜下见瓣叶两面的内皮细胞配布型式呈各向异性特征:腔面内皮纵向排列;壁面内皮横向排列。这种排列方式符合流体力学规律,以适应瓣膜在不同功能状态下,引导静脉血液返回心脏。12例正常瓣膜,在 Instron 1122型万能材料试验机上测得瓣膜承受最大拉力的平均值为1牛顿(范围0.75～1.35N)。在瓣膜置换或设计人工瓣膜时应考虑到上述各特点。
The human venous valve of the brachial,femoral and long saphenous veins were
examined with light,transmission and scanning electron microscopy.The observation
shows that the venous valve is composed of three functional layers covered with
endothelium on both surfaces.A loosely structured layer is located underlying the
endothelium.A network mainly containing randomly oriented elastic fibers was found
near the side towards the lumen.To the side towards the venous wall,there is a
dense layer composed of eircumferentially and transversly oriented collagen bundles.
Some smooth muscle cells extend from the wall of the vein to the base of the
venous valve.The elastic fibers and smooth muscle cells together with the collagen
fibers contribute to the mechanical load-bearing performance of the valve and to the
passive closing and openning mechanism.In addition,the smooth muscle cells might
play an active role in the normal functioning of the valve.
The scanning and transmission electron microscopy of venous valve show
different arrangement of the endothelium.On the surface of the valve next to the wall
of the vein,the endothelial cells are transversely arranged,while on the other
surface over which the current of blood flows,the cells are longitudinally arranged
in the direction of the current.These accord with the role of fluid mechanics.
12 normal venous valves were tested by universal testing instrument (Instron
type 1122).The mean value of the maximum tension of the valve is 1 N.The
average value of the tensile ultimate strength is 10N/mm^2.
出处
《解剖学报》
CAS
CSCD
北大核心
1989年第4期337-341,共5页
Acta Anatomica Sinica
关键词
静脉瓣
超微结构
平滑肌
最大拉力
Venous valve
Ultrastructure
Smooth muscle
Maximum tension
