acid base balance Flashcards
where does most of acid base balance take place
proximal convuluted tubule
how is acidosis prevented
secretion of H+/reabsorption of HCO3-
where is carbonic anhydrase and what does it do
in the renal tubule, converts carbonic acid into H2O and CO2
what happens to H2o and co2 produced in renal tubule
diffuses into epithelial cell and combine to make H2CO3 which is broken down by carbonic anhydrase into H+ and HCO3-
how does H+ get back into the proximal tubule
ATPase pump or Na+/H+ antiporter on the APICAL membrane
how does HCO3- get into the capillary from the proximal tubule
Na+/HCO3- symporter in the basolateral membrane
HCO3- moves down cg, this powers Na+ to move against cg
what cells manage acid base balance in the distal convoluted tubule
I cells
type A and type B
how is H+ secretion similar and different in the distal convoluted tubule to the proximal
both tubules use ATPase pumps to pump H+ into tubule
distal tubule uses a K+/H+ antiporter whereas Na+/H+ anti porter used in proximal tubule
how does HCo3- get reabsorbed into distal tubule
Cl-/HCO3- antiporter
HCO3- exchanged for Cl-
what causes respiratory acidosis
hypoventilation and respiratory depression
CO2 retention, elevated H+
what causes metabolic acidosis
dietary input of H+ exceeds H+ excretion e.g. Atkins diet
ketoacidiosis, type 1 diabetes
what causes respiratory alkalosis
hyperventilation, excess artificial ventilation
what causes metabolic alkalosis
excessive vomiting of acidic stomach contents, too many bicarbonate antacids
