<prompt> Dilution segment in nephrom is:Ascending LOHDescending LOHCollecting tubuleProximal tubule  <response>: The thick LOH is viually impermeable to H20, but large amounts of Na, Cl other ions are actively transpoed from the tubule into the medullary interstitium. Thus, fluid in thick ascending loop becomes very dilute and ka diluting segment of the nephron. Proximal tubules: 65 of the filtered electrolytes is reabsorbed here, along with water osmosis aquaporin - 1. Descending LOH: Water absorbed AQP - 1 much less permeable to Na urea; there by increasing the osmolarity. 