However, under normal conditions, it is slightly permeable to sodium ions. And sodium ions will be reabsorbed by our cells back into the surrounding tissue around our collecting duct, known as the interstituum. So about 5% of the total sodium ions inside the filtrate will be reabsorbed back into our body in the collecting duct. Now, as it turns out, the function of our collecting duct is actually controlled by two important types of hormones that we already spoke about. One of these hormones is ADH, the antidiatic hormone also known as vasopressin. And the other hormone that controls the functionality of the collecting duct is aldosterone.