白颈环毛蚓体壁肌肉细胞的超微结构

An ultrastructural study of musculature in Pheretima californica (Oligochaeta: Megascolecidae)

利用透射电镜观察了白颈环毛蚓(Pheretima californica)体壁肌肉层的超微结构。结果表明,肌肉为典型斜纹肌,肌细胞长梭形,细胞核、线粒体等细胞器位于细胞边缘,细胞绝大部分空间由具收缩功能的肌丝等占据,在肌细胞横切面,可以看到粗、细肌丝,肌浆网管和Z线,有序排成明暗相间的条纹,呈现特有的羽毛状结构,明暗带交替周期约0.35～0.40μm。文中对肌细胞内粗肌丝、细肌丝、肌浆网管和Z线的形态结构及其排列方式进行详细描述,并作了它们在松弛和收缩不同状态的比较。此外还对肌细胞周围基质中胶元微纤维作了描述。

This paper deals with the muscular ultrastructure of Pheretima callfornica. The result showes muscle fiber is obliquely striated and the muscle cells appear long-spearlike, with nucleus and mitochondria in the peripheral sarcoplasm. The most part of muscle cell is myofilaments which can extend and contract, A transverse section through muscle cell, thick myofilaments, thin my-ofilaments, tubule of sarcoplasmic reticulum and Z-rods are present the featherlike of light-bands and dark-bands alternately, with the period of 0. 35 - 0. 40 μm width. The ultrastructure and arrangement of them were investigated in detail and contrasted in the different slate of relaxion and contraction. In additional, the description of collagen fibres around the muscular cells was given.