Exam 3: Lecture 38

Question 1

What is the important buffer in urine and you do NOT want to lose?

Answer 1

HCO3-

BIcarb

Question 2

What is produced from protein and phospholipid catabolism

Answer 2

Excrted fixed H+

Question 3

How is H+ excreted from protein and phospholipid catabolism

Answer 3

NH4+

Question 4

How is excrete H+ titratable acid buffereed from protein and phospholipid catabolism

Answer 4

urinary phosphate

Question 5

What is the important mechanism that accompanies ecretion of H+

Answer 5

synthesis and reabsorption of NEW HCO3-

Question 6

Where is most reabsorption of HCO3- and is any new bicard produced?

Answer 6

early proximal convulated tubule

NO new

Question 7

What is the percent of filtered bicarb reabsorbed in the early PCT

Answer 7

99.9%

Question 8

What exchanger is in the luminal membrane to help with reabsorption in the PCT of bicarb

Answer 8

Na+/H+ exchanger

Question 9

What does bicarb combine with in the lumen to form carbonic acid

Answer 9

H+

Question 10

What does carbonic acid decompose into

Answer 10

CO2 and water

Question 11

when this reaction occurs in reverse - reform H2CO3 via carbonic anhydrase reforms to?

Answer 11

H+ and bicarb

Question 12

Where does H+ move back to after being broken down by carbonic anhydrase

Answer 12

lumen

Question 13

Where does bicarb go after being broken down by carbonic anhydrase

Answer 13

reabsorbed back into the blood

Question 14

What are the two important features of this mechanisms that allows for reabsorption of filtered HCO3-

Answer 14

1. net reabsorption of Na+ and HOC3-
2. No net secretion of H+ via this mechanism and recycling H+ to get bicarb back in

Question 15

What causes bicard and H+ to be made into CO2 and water?

Answer 15

carbonic anhydrase

Question 16

What causes water and CO2 to become bicarb and H=

Answer 16

carbonic anhydrase

Question 17

What happens to filtered bicarb

Answer 17

it is reabsorbed back into the blood

Question 18

When plasma bicarb is greater than 40 mEq/L, filtered load is high and reabsorption mechanism will become?

Answer 18

saturated

Question 19

When plasma bicarb is greater than 40 mEq/L, filtered load is high and reabsorption mechanism will become saturated. What does this occur in?

Answer 19

metabolic alkalosis

Question 20

What is defined as the need to excrete excess bicard and return to normal acid base balance

Answer 20

metabolic alkalosis

Question 21

ECF volume expansions (inhibits or stimulates) isosomtic reabsorption and bicarb reabsorption

Answer 21

inhibits

need to excrete water

Question 22

ECF volume contraction (inhibits or stimulates) isosmotic reabsorption and bicard reabsorption

Answer 22

stimulates

need to keep water

Question 23

Metabolism alkalosis that occurs secondary to ECF volume contractions - why does this occur?

Answer 23

decrease in ECF volume activates RAAS system

Angiotensin 2 stimulatues Na+/H+ exchnage in proximal tubule, which also stimulates bicarb reabsorption

Question 24

What happens to Na+/ water and Bicarb during treatment with loop of thiazide diuretics

Answer 24

Na+ and water excreted

bicarb is reabsorbed