② Proximal tubule近端小管 the largest, longest segment of nephron Function reabsorption --85%H,O, NaCl all G, AA, proteins excretion-H,NH4…② Proximal tubule 近端小管 the largest, longest segment of nephron Function: reabsorption --- 85%H2O, NaCl, all G, AA, proteins excretion--- H+ , NH4 +…