Fig. 3
From: A review of the reproductive system in anuran amphibians
Oviductal regions of frogs. The oviduct consists of three regions: the infundibulum, the ampulla, and the isthmus. These conform with the “pars convolute” and “pars recta”. The “pars recta” nurtures and transports the oocytes to the ovisac. The ostium tube is the transition from the “pars recta” into the infundibulum. Generally, the ostium tube is composed of numerous cilia and is aglandular. The infundibulum is formed of ciliated cells, glands, and secretory cells with lipid-secreting granules. The ampulla is a highly secretory portion of the “pars convoluta”. The exocrine glands and epithelium secrete a jelly-like substance to surround and nurture the oocyte. The isthmus has mucosal folds, ciliated cells with short cilia, and ceramide-secreting cells. Finally, the ovisac stores the oocytes, and the spermatheca store sperm for fertilization