摘要
报道了太平洋革囊星虫(Phascolosoma pacificum Keferstein)消化道各部的形态和组织学结构。结果表明,太平洋革囊星虫消化道分为口、咽、食道、肠、直肠和肛门,肠是消化道的主体,极长,可分为降肠和升肠,二者相互盘绕,使肠呈双螺旋状。消化道管壁由黏膜、黏膜下层、肌层和外膜组成,各部主要区别在于黏膜:咽和降肠上段黏膜为假复层纤毛柱状上皮;食道和直肠黏膜为单层纤毛柱状上皮;除降肠上段外,肠其他各段黏膜均为单层柱状上皮,降肠下段有呈倒"U"型的纤毛突起和"V"型的纤毛沟,升肠只存在纤毛沟;降肠下段与升肠上段黏膜上皮中有颗粒细胞存在,升肠纹状缘明显,直肠杯状细胞丰富。此外,皱襞的形态、黏膜下层和肌层的厚度等在消化道各部也存在差异。研究表明,太平洋革囊星虫消化道结构与其食性是相适应的。
This paper presented the form, gross structure and microstructure of the digestive tract of Phascolosoma pacificum. The digestive tracts could be divided into mouth, pharynx, esophagus, intestine, rectum and anus. As the principal part in digestive tracts, intestine was exceedingly long, and could fall into the descending intestine and ascending intestine. Both of the descending intestine and ascending intestine coiled mutually, making the intestine helix in shape. The wall of digestive tract consisted of mucosa, submucosa, tunica muscularis and tunica adventitia. The main differences among all parts lied in mucosa. The mucosa on pharynx and the superior segment of ascending intestine was stratified ciliated columnar euithelium, while mucosa on esophagus and rectum was monolayer ciliated columnar epithelium. Except the superior segment of descending intestine, mucosa of intestine and all other segments was monolayer columnar epithelium. There were inverse u-shaped ciliated apophysis and v-shaped ciliated grooves on the inferior segment of descending intestine, while only v-shaped ciliated groove existed on the ascending intestine. Besides, a great deal of granulous cells occurred on the epitheli- um of the inferior segment of descending intestine and the superior segment of descending intestine. The form of plica, the submucosa and the thickness of tunica muscularis were also different in various parts of the digestive tract. This study showed that the digestive tract structure of P. pacificum was adapted to its feeding habits.
出处
《海洋水产研究》
CSCD
北大核心
2007年第1期65-70,共6页
Marine Fisheries Research
基金
教育部优秀青年教师资助计划项目(EYTP)(序号1791)资助
关键词
太平洋革囊星虫
消化道
解剖学
Phascolosoma pacificum
Keferstein
Digestive tract
Anatomy
