Monday, January 18, 2016

Transport in kidney

transport in kidney

Filtered Load = GFR x plasma concentration

  • Transport maximum = max filtered load that nephron can reabsorb = 375 mg/min for glucose
HCO3 reabsorption in proximal tubule
  • can't cross cell membrane (neg chg)
  • combines with H+ to form CO2 & H2O
  • CO2 = non-polar molecule = diffuses across membrane


Clearance Ratios
• Comparison of clearance of various solutes to clearance of Inulin
• Why inulin?
• Cx/Cinulin = 1.0
– Substance can be used as a filtration marker
– Not reabsorbed, secreted or metabolized: creatinine
• Cx/Cinulin < 1.0
– Either the substance is not filtered OR it is filtered and subsequently reabsorbed: glucose
• Cx/Cinulin > 1.0
– Substance is filtered (or not) and secreted: organic acids
– Penicillin!


Proximal Tubule
67% of Na and H2O reabsorption


Loop of Henle


Early Distal Tubule

Late Distal Tubule


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1 comment:

  1. UnknownSeptember 27, 2017 at 6:37 AM

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