Renal Tubular Disoders Flashcards
What is the role of the proximal tubules
Active reabsorption of multiple solutes
What generates the sodium gradient in proximal tubules
Na/K ATPases
What organelle is plentiful in the PCT and why
Mitochondria as proximal tubules are metabolically active cells
What condition is related to failure of glucose reabsorption
Renal glycosuria
Describe bicarbonate reabsorption
In the tubular lumen, HCO3- and H+ will combine under the influence of carbonic anhydrase to form CO2 and H2O
H2O + CO2 can be passively reabsorbed into proximal tubular cells where they combine to form carbonic acid
Carbonic anhydrase within the tubular cells breaks down this acid to reform H+ and HCO3-
Anti porter returns H+ to the tubular lumen and reabsorbs Na into the cells which is then actively reabsorbed into the bloodstream
HCO3- also gets reabsorbed into the bloodstream
What condition is caused be a failure of bicarbonate reabsorption
Proximal renal tubular acidosis
Function of the loop of henle
Generates medullary [gradient]
Active Na reabsorption in thick ascending limb
What is the role of the NKCC2 transporter in the thick ascending limb
Pulls in a Na+, 2x Cl- and a K+ from the tubular lumen into the cell
K+ is recycled into the tubular lumen if the TAL by which transporter
ROMK
How is a negative electrochemical gradient generated in the interstitial fluid of the TAL
1 Na is reabsorbed for every 2 Cl- so the overall charge is negative
This electrochemical gradient in the interstitial fluid drives paracellular transmission of which 2 ions
Calcium
Magnesium
What is the defect in barrters syndrome
NKCC2, ROMK, CLCKa/b
What transporters reabsorb Cl- from the cell into interstitial fluid
ClCKa/b which both have a subunit called barrtin
Function of the DCT
fine tuning of Na reabsorption and K+ and acid base balance
Function of collecting duct
Mediates water reabsorption and [urine]