光裸星虫消化系统的解剖学和组织学研究

Anatomical and Histological Study on Digestive System of Sipunculus nudus

运用解剖学和组织学方法研究光裸星虫(Sipunculus nudus)消化系统结构。结果表明,光裸星虫消化系统由消化道和直肠盲囊组成,消化道可分为口、食道、下行肠、上行肠、直肠和肛门。口四周由具摄食作用的辐射状触手围绕。消化道管壁由黏膜层、黏膜下层和浆膜三层结构组成,黏膜层具有大量皱褶,黏膜下层和浆膜层中分布有大量颗粒细胞;无连续的肌肉层,只在黏膜下层内散布着数量不等的肌纤维。直肠盲囊细长,连接于上行肠末端,囊壁无分泌细胞,囊内充满黄色黏稠液状物质。

Anatomical and histological observation on the digestive system of Sipunculus nudus was conducted with light microscopy. The result showed that the digestive system consisted of the digestive tract and the rectal caecum, the digestive tract could be divided into mouth, esophagus, descending intestine, ascending intestine, rectum and anus. Tentacle surrounding the mouth radialized as a feeding organ. Digestive tract consisted of mucosa, submucosa and tunica adventitia without consecutive tunica muscularis in the wall. Muscle fibrin distributed asymmetrically was found in the submucosa and many granular cell distributed in submucosa and tunica adventitia. Rectal caecus is slender and link to end of the ascending intestine. In rectal caecus full of yellow mucus and no secretory cell was found in the wall.