Bicarbonate Keef

Question 1

ACid base balance:
what is the first line of defense?
what is the second line of defense?
what is the third line of defense?

Answer 1

chemical buffering
regulation of CO2 levels by lung
Reg. of bicarb via kidney

Question 2

The kidneys can excrete (blank) and (blank) and it can make (blank)

Answer 2

bicarb and acid

bicarb

Question 3

when you are in severe acidosis what will your kidney do?

Answer 3

you will get bicarbonate reabsorption!!!!

Question 4

What will happen within the proximal tubule of the kidney when it is undergoing bicarb reabsorption?

Answer 4

The Na K atpase will create a gradient to allow Na to be reabsorbed, this reabsorption of sodium will allow for antiport of hydrogen to place hydrogen into the lumen of the proximal tubule. The hydrogen will combine with bicarb within the tubule to create carbonic anhydrase which will be broken down into CO2 and H20 which will then be reabsorbed,within the cells of the proximal tubule this can be reversed or enhanced so you can get increased reaborption or filtered H+ or Bicarb. Lumen will be down to a pH of 6

Question 5

Which is the acid secreting cell:

The principal or intercalated cell?

Answer 5

the intercalated cell

Question 6

What will happen within the distal nephron of the kidney when it is undergoing bicarb reabsorption?

Answer 6

The same as in the proximal tubule but instead of antiport occurring with sodium and hydrogen, the antiport occurs with potassium and hydrogen. In the distal nephron you will have very low pH around 4.4

Question 7

The (blank) excrete excess bicarbonate during alkalosis

Answer 7

kidneys

Question 8

What will diamox do?

Answer 8

block carbonic anhydrase so you can return your alkalotic patients back to a normal pH

Question 9

What are the two methods that the kidney uses to eliminate fixed acids?

Answer 9

formation of titratable acid

formation of ammonium (NH4+)

Question 10

(blank) is the predominate titratable acid in tubular fluid.

Answer 10

phosphate

Question 11

Where do you create the titratable acids in the kidney?

Answer 11

in the lumen

Question 12

A method for eliminating fixed acid from the body is via formation and excretion of (blank) utilizing glutamine and chloride

Answer 12

ammonium ion (NH4+)

Question 13

Where do you get NH4+ secretion?

Answer 13

in the proximal tubule

Question 14

Where do you get the H, ATPase pump?

Answer 14

in the distal tubule

Question 15

(blank) stimulated H+ secretion

Answer 15

aldosterone

Question 16

The biggest job the kidneys perform is to reabsorb filtered (blank)

Answer 16

bicarbonate

Question 17

To find the reabsorption rate of HCO3- how do you find it?

Answer 17

just by calculating the filtered low which is GFR X P

Question 18

The (blank) simultaneously make new bicarb and excrete acid

Answer 18

kidneys

Question 19

Net acid excretion is equal to (blank)

Answer 19

new HCO3- generation

Question 20

How do you calculate net acid excretion?

Answer 20

Titratable acid + NH4+

Question 21

reabsorbed bicarbonate far exceeds (blank)

Answer 21

new bicarbonate

Question 22

How do you find total HCO3- delivered to plasma?

Answer 22

add new HCO3 + reabsorbed HCO3-

Question 23

The amount of (blank) far exceeds the amount of acid that is excreted

Answer 23

H+ secreted

Question 24

How do you find the total amount of H+ secreted?

Answer 24

H+ secretion associated with new HCO3 + H associated with reabsorbed HCO3

Question 25

How do we measure fixed acid in the urine?

Answer 25

titratible acid is determined by titrating urine back to pH 7.4, NH4+ excretion is determined by measuring NH4+ content

Question 26

What is the normal H combined with NH3?

What is the normal H associated with titratable acid?

Answer 26

30-50

10-30

Question 27

If your acid is really high what do you have?

If you have very low acid what do you have?

Answer 27

diabetic acidosis

chronic renal disease

Question 28

If you have a K+ losing diuretic what will you be excreting? If you have a K+ sparing diuretic is this reversed? What do both diuretics have in common?

Answer 28

1) potassium and hydrogen
2) yes! you will have decreased potassium and hydrogen excretion->acidosis and hyperkalemia
3) increase in NaCl, flow and decrease in volume pressure