Over half of the potassium that appears in the urine of a patient, who has ingested some potassium salts, is derived From?

Secretion by the distal tubule.With a normal potassium intake filtered K+ (which is not reabsorbed) accounts for two third and secreted K+ counts for one-third of the excreted urinary K+.However, on high potassium diet, the K+ secretion increases and K+ secretion account for about 60-65% excreted K+.K+ secretion occurs in distal tubules and collecting duct.