Renal physiology, biochemistry, and anatomy are reviewed. For the most part, those aspects of these disciplines will be discussed which relate directly to the question of the evaluation of nephrotoxicity. In addition, emphasis is placed on those procedures and techniques which are useful in the evaluation of nephrotoxicity. A detailed discussion of histological and anatomical considerations is not given, since this is probably the least useful criterion for evaluation of renal damage. This information is intended as background for the remainder of the symposium which will be directed toward an understanding of specific nephrotoxicity phenomena.There are several references or textbooks in which suitable review material is available (1-4), all relatively up-to-date, and which present renal physiology and biochemistry in various degrees of thoroughness and complexity. The two monographs by Valtin and Sullivan are relatively fundamental, but both are thorough. Pitts' text is not only complete, but is also much more detailed than the previous two texts. The Handbook of Physiology presents the most detail of these four. Furthermore, this reference work contains many citations to the original literature, and can be used therefore as a guide to much of the original literature which pertains to renal physiology, biochemistry, and anatomy.The intrarenal localization of the nephron is depicted in Figure 1. The anatomical arrangements of the various nephron types are presented as they appear in situ. All nephrons have their glomeruli, proximal tubules, and distal tubules in the cortex. Only the loops of Henle of