Burighel P, Milanesi C
Cell Tissue Res. 1977 Aug 26;182(3):357-69. doi: 10.1007/BF00219771.
In the intestine of the filtering zooids of B. schlosseri three segments can be distinguished. In the intermediate segment the epithelium, which is encrusted by the ampullae of the pyloric gland, shows marked aspects of alteration. In the proximal and distal segments, ciliated mucous, vacuolated and endocrine-like cells are recognizable. Ciliated mucous cells, widely distributed along the intestine, possess the apical region filled with numerous mucous granules, which are extruded with merocrine modality. Variations in morphology of the granules are visible especially between cells of different regions. Vacuolated cells appear involved in absorptive function. They are characterized by developed microvilli, numerous apical small vesicles and great supranuclear vacuoles containing heterogeneous material. The vacuolated cells of the proximal segment resemble the gastric vacuolated cells of B. schlosseri. The vacuolated cells of the distal segment show many morphological similarities with protein absorbing cells of various animals for the presence of a giant vacuole and an apical network of vesicles and tubules with fuzzy coating on the luminal face. The intestinal endocrine-like cells are rare and characterized by strongly electron dense granules distributed in all the cytoplasm, but predominantly in the basal region.
在施氏苔藓虫过滤类个虫的肠道中可区分出三个部分。在中间部分，被幽门腺壶腹覆盖的上皮呈现出明显的改变迹象。在近端和远端部分，可识别出纤毛黏液细胞、空泡化细胞和类内分泌细胞。纤毛黏液细胞广泛分布于肠道中，其顶端区域充满大量黏液颗粒，这些颗粒通过局部分泌方式排出。颗粒形态的变化尤其在不同区域的细胞之间可见。空泡化细胞似乎参与吸收功能。它们的特征是具有发达的微绒毛、大量顶端小泡以及含有异质物质的巨大核上空泡。近端部分的空泡化细胞类似于施氏苔藓虫的胃空泡化细胞。远端部分的空泡化细胞与各种动物的蛋白质吸收细胞在形态上有许多相似之处，因为存在一个巨大的空泡以及顶端的小泡和小管网络，其腔面有模糊的包被。肠道类内分泌细胞很少见，其特征是强电子致密颗粒分布于整个细胞质中，但主要分布在基部区域。
