长鳍吻鮈消化系统组织学初步研究

长鳍吻鮈消化道由口咽腔、食道、肠和肛门几部分组成,食道粗短,肠较长,在活体内呈"N"形盘旋状;消化腺分为肝脏和胰腺,肝脏暗褐色,分被、腹两叶,胰为弥漫型,分布于口咽、食道肠壁和肝脏内,肉眼不可分辨;食道上皮为复层上皮,而肠上皮为单层柱状上皮,少量杯状细胞分布于食道、肠前段、肠中段上皮细胞之间,肠后段杯状细胞丰富;消化道肌肉层分2层,内层为环肌,外层为纵肌。肌肉层从肠前段到肠后段逐渐加厚;肝小叶不明显,肝细胞呈卵圆形或多角形。

A Primary Histological Study of the Digestive System of Rhinogobio Ventralis

The alimentary canal of Rhinogobio ventralis Sauvage et Dabry includes oral-pharyngeal cavity,esophagus,intestines,and anus.Esophagus is short,while the 'N'-shaped intestine is long.Digestive glands include liver and pancreas.Dust-color liver is composed of two parts,which are hepatic dorsal lobule and hepatic ventral lobule.Pancreas,which cannot be seen by eyes directly,is dispersed in esophagus,intestine and liver.The epithelium of the esophagus is stratified squamous,but the epithelium of intestine is simple columnar.There are fewer calycular cells among epithelial cells of esophagus,gut anterior segment and gut middle segment,while there are abundant calycular cells in the gut posterior segment.The muscle of the digestive tract has 2 layers,one is annuloid muscle and the other is vertical muscle.The muscular layer is thicker and thicker from gut anterior segment to gut posterior segment.The hepatic lobule is not clear.Hepatic cells are egg-like or polygon.