Final Review: Renal Acid/Base Regulation Flashcards
What enzyme is important in the formation of carbonic acid from CO2 & H2O?
Carbonic anhydrase
What is the most important extracellular buffer system in the body?
Bicarbonate buffer system
Increased levels of HCO3- can be excreted by the kidneys resulting in…?
Decrease in blood CO2 levels, therefore, decreased respiration rate
What does the phosphate buffer system play a major role in?
Renal tubular fluid*
Intracellular fluids
What is the main method for removing nonvolatile acids?
Renal excretion
What parts of the renal tubules does H+ ion secretion (via secondary active transport) NOT occur?
Descending & ascending thin limbs of the loop of Henle
Where does primary H+ ion secretion begin?
Late distal tubules & intercalated cells
What does primary H+ active transport involve?
hydrogen-transporting ATPase
Where does ~80-90% of bicarbonate reabsorption occur?
Proximal tubule
What is metabolic acidosis/alkalosis?
Change in plasma pH due to increase (alkalosis) or decrease (acidosis) in bicarbonate ion
In metabolic acidosis, bicarbonate ion is _______ extracellular fluid.
Added to
In metabolic alkalosis, bicarbonate ion is _______ extracellular fluid.
Removed from
What is the lower limit of pH that can be achieved in normal kidneys?
4.5
What is respiratory acidosis/alkalosis?
Change in plasma pH due to increase (acidosis) or decrease (alkalosis) in CO2
How do the kidneys respond to respiratory acidosis?
By adding new bicarbonate ion to extracellular fluid
What is a compensatory response to metabolic alkalosis?
Decreased ventilation
