This lecture covers the function of the renal system, focusing on the production of primary and final urine. It explains the constitutive equations and determinants of renal function, the determinants of renal filtration at the glomerulus level, and the role of the renal tubule in urine processing. The process of transforming primary urine into final urine is also discussed, along with the principles of glomerular filtration and the factors affecting the composition of urine.