The Reptilian Renal Portal System - A Review
Assoc Reptilian Amphibian Vet 9[1]:4-9 Spring'99 Review Article 36 Refs

- The anatomy of the reptilian renal portal system is reviewed. Its structure is fundamentally similar in all species examined. The renal portal system functions to provide blood to tubule cells during periods of dehydration to prevent them undergoing ischemic necrosis. Blood flows from the tail and hindlimbs through the kidneys and then on to the heart. However, anastomoses exist capable of shunting blood around the kidneys to the liver. Current data suggests that the renal portal system does not affect drug kinetics. A renal portal system is present in most fish and all amphibians, reptiles and birds. It is absent in mammals, except embryologically. The anatomy of the reptilian renal portal system has been described for a number of different species. Although it is fundamentally similar among the various groups of reptiles, some differences do exist. In general, blood flows from the tail by the caudal vein and from the limbs, where present, by the iliac or femoral veins. These vessels connect to the afferent renal portal veins which convey blood into the kidneys. Once the blood has filtered through the kidneys, it emerges in the efferent renal portal veins and flows to the heart via the post caval vein. The literature describing the anatomy of the renal portal system is quite confusing, since various authors have given different names to the same vessel, making interpretation somewhat challenging. In many instances, only scientific names were used for the species described. Common names could not always be determined and so are missing in some instances. Those that are used are based on common current taxonomy.