<prompt> Glucose is absorbed from?Upper pa of PCTAscending limb of LOHCoical Collecting ductMedullary collecting duct  <response>: - Tubular reabsorption a highly selective - Some substances like glucose, AA, Na2, H20 is absorbed maximum from upper pa of PCT As proximal tubule epithelial cells have: - Large number of mitochondria to suppo powerful active transpo processes highly metabolic - Have brush borders provide extensive surface area for absorption - As glucose is reabsorbed by secondary active transpo, it is absorbed almost all by proximal convoluted tubule. Ascending limb of loop of Henle have: - Thin segment a moderate permeable to solutes increase permeable to H2O - Thick segment a viually impermeable to H2O, permeable to solutes a diluting segment of nephron. Coical collecting duct: - Contain principle cells reabsorb Na2 secrete K - Intercalated cells secrete absorb H, HCO3- K ions based on PH Medullary collecting duct - Under ADH influence Reabsorb H20 urine vol urine concentration - Permeable to urea, hence urea is reabsorbed into interstitium increase osmolality of interstitium, helps in concentrating urine - Regulate acid base balance by secreting H ions 