Renal Regulation of pH

Question 1

What is the equation for ‘acidosis’?

Answer 1

H20 + CO2 H2CO3 H+ + HCO3-

Question 2

What occurs during Respiratory Acidosis?

Answer 2

INCREASED CO2

THUS, shifts equation to RHS
Increasing ionisation of H2CO3 to H+ and HCO3-

THUS, find acidosis with increased HCO3-

Question 3

What occurs during Metabolic Acidosis?

Answer 3

INCREASED H+

THUS, shifts equation to LHS
Increasing the buffering of excess H+ with HCO3-

THUS, find acidosis with decreased HCO3-

Question 4

What occurs during renal compensation for an ACIDOSIS?

Answer 4

plasma pH LOW (H+ HIGH)

kidney secretes lots H+

All HCO3- reabsorbed

Excess H+ excreted, adding HCO3- back into plasma

Question 5

What is the function of TYPE A intercalated cells (in the DCT)?

Answer 5

Secrete H+

Reabsorb HCO3-

Reabsorb K+

Question 6

What is the function of TYPE B intercalated cells (in the DCT)?

Answer 6

Secrete HCO3- and K+

Reabsorb H+

Only active during alkalosis

Not the main site of K+ secretion

Question 7

What occurs during renal compensation for an ALKALOSIS?

Answer 7

plasma pH HIGH (H+ LOW)

kidney secretes less H+

Some filtered HCO3- NOT reabsorbed

Plasma HCO3- decrease, THUS reaction moves towards H+ + HCO3- side, generating H+

Question 8

SEE DIAGRAM!!!!!!

[Renal compensation for an ACIDOSIS]

Answer 8

:)

Question 9

SEE DIAGRAM FOR ACIDOSIS/ALKALOSIS TABLE!!!!!!!

Answer 9

:D

Question 10

What are the 2 chemical buffer systems present in the urine?

Answer 10

1. PHOSPHATE

2. AMMONIA SYNTHESIS

Question 11

What is the PHOSPHATE buffer system?

Answer 11

-excess phosphate in our diet
-filtrate lvls remain above renal threshold
-high lvls of phosphate in urine buffer H+ ions;
Na2HPO4 + H Na2H2PO4

Question 12

What is the AMMONIA SYNTHESIS buffer system?

Answer 12

-NH3 is synthesised in tubular cells from the a.a glutamate, in response to high filtrate H+
NH3 + H NH4