The main function of the renal tubules is to filter toxins and water, and the filtered water in turn forms primary urine. The renal vesicle is a very important functional unit of the kidney, which mainly consists of capillaries and the renal capsule, with the capillaries in the middle and the renal capsule wrapped around the periphery. Blood from the body enters the kidneys and enters the capillaries, and after filtering, it enters the cavity of the renal capsule, which can filter toxins and remove excess water. After the excess water enters the renal capsule, it forms primary urine, which is called primary urine because this urine still has to be reabsorbed by the renal tubules before it can finally form real urine. From here, we can see that the function of the renal tubules in the human body is very important. If the renal vesicles become diseased, there will be accumulation of toxins in the body, that is, renal failure, and the impact on the body is very great.