Greven H
Cell Tissue Res. 1976 Feb 25;166(3):339-51. doi: 10.1007/BF00220130.
The midgut epithelial cells of the eutardigrade Isophypsibius augusti are organized into a convoluted monolayer. Only a single cell type could be distinguished although this cell type displayed considerable morphological variation. The midgut begins with crescent-shaped cells. More distally the cells are of variable height depending on the stored amount of nutritional material. No regenerative cells are present. Adjoining cells are held together by apical zonulae continuae. All the cells are characterized by a striated border, some basal infoldings, cytosis vesicles, numerous mitochondria, and abundant rough endoplasmic reticulum. Dictyosomes occur in small numbers. Ovoid or spherical inclusions (spherites), often concentrically laminated, are common. The cells, especially those along the middle part of the gut, are filled with large amounts of nutritional storage which includes polysaccharide material. The possible functions of the midgut in Tardigrada are discussed.
缓步动物奥氏等节缓步虫的中肠上皮细胞组织成一个盘绕的单层。尽管这种细胞类型表现出相当大的形态变异，但只能区分出一种细胞类型。中肠始于新月形细胞。在更远端，细胞高度因营养物质的储存量而异。不存在再生细胞。相邻细胞通过顶端连续小带连接在一起。所有细胞的特征是有纹状缘、一些基底内褶、胞吞小泡、大量线粒体和丰富的粗面内质网。高尔基体数量较少。卵形或球形内含物（球状体）很常见，通常呈同心层状。细胞，尤其是沿着肠道中部的细胞，充满了大量包括多糖物质在内的营养储存物。文中讨论了缓步动物中肠的可能功能。
