可口革囊星虫消化道的形态及组织学结构

对可口革囊星虫(Phascolosoma esculenta)消化道各部分结构进行了形态学和组织学观察,表明可口革囊星虫消化道由翻吻、咽、食道、肠、直肠和肛门组成。翻吻收缩性很强;肠道极长,沿纺锤肌螺旋缠绕成肠索。消化道管壁由内向外分为粘膜层、粘膜下层、肌层和外膜。粘膜上皮主要由柱状细胞组成。除肠外,消化道上皮细胞均有发达的纤毛,肠上皮细胞主要具发达的微绒毛;粘膜下层及肌层的发达程度因消化道的部位不同而异。

The Morphological and Histological Characteristics of Digestive Tract in Phascolosoma esculenta

Morphological and histological observation on the digestive tract of Phascolosoma esculenta was conducted with light microscopy.The digestive tract can be divided into introvert,pharynx,esophagus,intestine,rectum and anus.The introvert is contractible and the long intestine coils around a long,slender,central spindle muscle to form the "intestine loop".The wall of digestive tract is composed of mucosa,submucosa,muscularis and adventitia.The epithelium of the mucosa membrane is mainly composed of columnar cells with developed microvilli except for the intestine part.In the intestine,the epithelium cells have developed microvilli,but the development of submucosa and muscularis is different at different portions.