食蚊鱼泌尿系统结构

食蚊鱼泌尿系统包括中肾、输尿管、膀胱。中肾分化程度较低，包括肾小体和肾小管，无皮质、髓质之分，有肾小体聚集现象。肾小管由颈段、第一近曲小管、第二近曲小管、间段、远曲小管及搜集管组成。第一近曲小管上皮中有嗜伊红油滴细胞。肾中散布有淋巴髓样组织、甲状腺滤泡，因此肾脏为多种生理功能的复合性器官。输尿管位于两肾叶腹侧，粘膜层为单层柱状或假复层柱状上皮，缺粘膜下层，无纵肌，外膜甚薄或缺如。左右输尿管在后端合并，移行一段后突出形成膀胱。膀胱内壁具绒毛，绒毛表面为移行上皮。

STRUCTURE OF THE URINARY SYSTEM OF GAMBUSIA AFFINIS

The urinary system of Gambusia affinis was found to consist of kidney, ureter and bladder. Differentiation of the mesonephros , or kidney, which includes renal corpuscle and renal tubules, appeared at a low level and it had no zones of cortex and medulla. Aggregation of renal corpuscles was observed in the kidney. The renal tubules were composed of the neck, the first and the second proximal, intermediate and distal segments and the collecting duct. Eosinophil cells were found in the epithelium of the first proximal segment. Lymphoid tissue and thyroid gland interspersed in the kidney, indicating that it is a multi-functional organ. The two ureters were located at the ventral position of the kidneys. The musoca was single columnar or pseudo-stratified columnar epithelium without the subucosa. No longitudinal muscles were present and the serosa, if any, was very thin. The two ureters fused at the end and ran a course into the bladder, which had villi epithelium. The surface of the villi is a transitional epithelium.