Renal 5: Acid-Base Balance

Question 1

body fluid pH is tightly regulated by ___

Answer 1

buffering

Question 2

___ is the most important physiological pH buffer

Answer 2

bicarbonate

Question 3

bicarbonate buffering is regulated by the ___ and ___

Answer 3

kidneys and lungs

Question 4

what happens to practically all of the HCO3 filtered by the kidneys?

Answer 4

reabsorbed by different mechanisms

Question 5

secreted H is excreted as __ or ___

Answer 5

titratable acid or as NH4+

Question 6

acid-base disorders have several causes and result in renal and respiratory ___ mechanisms

Answer 6

compensatory

Question 7

the kidneys respond to changes in blood pH by ___ and ___

Answer 7

inceasing or decreasing acid secretion and HCo3 reabsorption

Question 8

what is the pH range of urine?

Answer 8

4.5-8

Question 9

what are the 2 acid inputs to plasma?

Answer 9

diet (fatty and amino acids) and metabolism (CO2, H2O, Lactic acids, ketoacids)

Question 10

what are the 2 acid outputs from the plasma?

Answer 10

expiration of volatile acids from the lungs & excretion of fixed acids by the kidneys

Question 11

the phosphate buffers are important in __ and ))

Answer 11

intracellular fluid and urine

Question 12

what enzyme changes co2 and water into carbonic acid?

Answer 12

carbonic anhydrase

Question 13

carbonic acid dissociates into __ and __

Answer 13

bicarbonate and H+

Question 14

buffers prevent ___ in pH when H+ levels change

Answer 14

large changes

Question 15

at low pH, what is the dominant form?

Answer 15

weak acid (protonated)

Question 16

at high pH what is the dominant form?

Answer 16

weak base, (deprotonated)

Question 17

the ___ equation relates the buffer levels to overall pH

Answer 17

henderson hasslebach

Question 18

at low pH is CO2 or Bicarb dominant?

Answer 18

CO2

Question 19

at high pH is CO2 or Bicarb dominant?

Answer 19

Bicarb

Question 20

what happens to CO2 and hCO3- when acid is added? 1

Answer 20

HCO3 is reabs and CO2 expired

Question 21

what happens to CO2 and HCO3- when base is added?

Answer 21

HCo3 excreted and Co2 decreased reabsorption

Question 22

at pH 7.4, what is the dominant form of the bicarbonate buffer?

Answer 22

HCO3-

Question 23

most of the HCO3 is reabsorbed in ____ of the nephron

Answer 23

proximal tubule

Question 24

secretion of H is done by ___ transporters in the __ membrane of the proximal tubule

Answer 24

Na/H antiporter; apical

Question 25

the secretion of H is driven by the formation of ___ in the cell in the proximal tubule

Answer 25

H2CO3

Question 26

bicarbonate is reabsorbed across the __ membrane by ___ in the proximal tube

Answer 26

basolateral; facillitated diffsuin transporte

Question 27

the H ions that secreted are used to reclaim HCO3 to make ___ and __

Answer 27

co2 and water

Question 28

the conversion of H2CO3 to h20 and Co2 is performed by ___ which is tethered to the apical membrane

Answer 28

carbonic anhydrase

Question 29

the Co2 made when H is secreted is used to make more __ within the cell

Answer 29

carbonic acid (that will make bicarb and more H for more cycling)

Question 30

net secretion of H; charge of tubular fluid pH__ in the proximal tube

Answer 30

none; none

Question 31

how is H secreted across the apical membrane in the collecting duct?

Answer 31

proton pump (H ATPase)

Question 32

how is bicarb reabsorbed across the baso membrane in the collecting duct?

Answer 32

HCO3 Cl transporter

Question 33

in the collecting duct, the secretion of H is coupled to __

Answer 33

formation and reabsorption of HCo3

Question 34

Alpha intercalted cells act reverse to__

Answer 34

acidosis

Question 35

beta intercalated cells act to reverse __

Answer 35

alkalosis

Question 36

___ is secreted and __ is reabsorbed by the alpha intercalated cells

Answer 36

H; HCO3

Question 37

___ is secreted and ___ is reabsorbed by the beta intercalated cells

Answer 37

hco3; H

Question 38

what transporter is used to secrete HCO3 from the beta intercalated cells?

Answer 38

pendrin

Question 39

t/f pendrin is special to the apical membrane

Answer 39

t

Question 40

is the alpha or beta intercalated cell dominant under most cases?

Answer 40

alpha

Question 41

in diabetic patients, the the total production of H and excretion as either titratable acids or NH4 is much ___ compared to normal

Answer 41

higher

Question 42

how does the total production of H and excretion as Nh4 and titratable acids in patients with renal failure compare to that of a normal patient?

Answer 42

total H is the same; but excretion in these forms is lower

Question 43

metabolic acidosis is caused by __

Answer 43

decresed HCO3

Question 44

metabolic alkalosis is caused by __

Answer 44

increased HCO3

Question 45

respiratory acidosis is caused by

Answer 45

increased PCO2

Question 46

respiratory alkalosis is caused by

Answer 46

decreased PCO2

Question 47

give 2 possible conditions leading to metabolic acidosis

Answer 47

diarrhea (loss of hCO3) and ketoacidosis (raised H)

Question 48

give 2 possible conditions leading to metabolic alkalosis

Answer 48

vomiting (loss of H) and eating too much HCO3

Question 49

give an example of a condition that may cause respiratory acidosis

Answer 49

COPD / hypoventillation

Question 50

give an example of a condition that may cause respiratory alkalosis

Answer 50

hyperventillation

Question 51

what is the respiratory compensation for metaboilc alkalosis?

Answer 51

hypoventilation

Question 52

what is the respiratory compensation for metabolic acidosis?

Answer 52

hyperventilation

Question 53

in response to acidosis, phosphate reabsorption is ___ by the proximal tubule

Answer 53

decreased (to maintain buffering in urine)

Question 54

in response to alkalosis, phosphate reabsorption id ___ by the proximal tubule

Answer 54

icreased

Question 55

pH above 7.4 is

Answer 55

alkalosis

Question 56

pH below 7.4 is

Answer 56

acidosis

Question 57

{HCO3} above 24 mEq/L is

Answer 57

metabolic alkalosis

Question 58

[HCO3] below 24 mEq/L is

Answer 58

metabolic acidosis

Question 59

PCO2 below 40 mmhg is

Answer 59

respiratory alkalosis

Question 60

PCO2 above 40 mmHG is __-

Answer 60

respiratory acidosis