双团棘胸蛙消化道解剖学及组织学观察

Anatomical Features and Histological Structure of the Digestive Canal of Paa yunnanensis Anderson

双团棘胸蛙的肠分为十二指肠、回肠、大肠和直肠.口腔顶壁为复层纤毛上皮,底壁为复层扁平上皮,食道为假复层纤毛柱状上皮,胃和肠均为单层柱状上皮,泄殖腔为复层扁平上皮.各段皱褶丰富,仅食道和胃本体有巨型的树枝状皱褶.口腔顶壁、食道、胃及泄殖腔有发达的腺体,肠的各段无多细胞腺体分布但杯状细胞丰富,其中大肠最少,直肠部最多.在口腔顶壁、食道及十二指肠均有丰富的巨型杯状细胞,胃各部及泄殖腔均无杯状细胞分布.

The results of histo-morphological studies demonstrated that the small intestine of Paa yunnanensis Anderson consisted of duodenum and ileum while the large intestine was differentiated into rectum. The mucosa of the oral cavity and various parts of the digestive canal were well differentiated in their cellular characteristics that were described within each region. The apical oral cavity epithelium was stratified ciliated epithelium and the oesophagusis＇s was pseudo-stratified ciliated columnar epithelium. Simple columnar epithelium belonged to every part of stomach and intestine. Cloacal chamber epithelium was stratified cuboidal epithelium. Each organ had plenty of rugae besides that oesophagus and stomach had multiarborization rugae. Plenteous glands were detected in the apical oral cavity, oesophagus, stomach and cloaeal chamber. All segments of the intestine did not have multieellular gland but had plenteous goblet cells. Few common goblet cells were distributed in the anterior large intestine, but numerous common goblet cells were detected in the rectum. Large goblet cells lay in the apical oral cavity, oesophagus and duodenum. No goblet cells lay in the stomach and the cloacal chamber.