So, once again, let's summarize our discussion. So, the loop of hemle is this Ushaped structure that is found inside the medulla portion of the kidney. And it uses a countercurrent multiplier system. It uses this system in which the filter travels downward here, but upward here, to multiply to increase the amount of water that is reabsorbed back by our body from the filtrate. At the same time, it concentrates the urine in the collecting duck. And this basically is done without using too much energy.