In fact, as we go lower along aramidoula, as we go deeper into aramidoula, the concentration of ions increases. Now, if we have a higher concentration of ions outside in the surrounding tissue than in the inside of the lumen of our collecting duct, then water will tend to flow from a lower concentration of solute to a higher concentration of solute. And that's because the sommotic pressure on the outside will be higher. So once again, ADH stimulates the epithelial cells to produce membrane protein channels known as aquaphorns. These channels allow the passive transport of water down its gradient to the outside to our interstituent from the filtrate found in the lumen of the collecting duct. And this is because of the fact that the loop of Henley established this electrochemical gradient.