lecture 19 (T3): renal acid-base regulation Flashcards Preview

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Flashcards in lecture 19 (T3): renal acid-base regulation Deck (49):
1

which buffer system is most important in buffering renal tubular fluid

phosphate buffer system

2

compounds that dissociate incompletely into hydrogen ions and a conjugate base are members of what compound

weak acids

3

bicarbonate buffer system consists of ____ and _____

bicarbonate salt and weak acid

4

what occurs when there is a decrease in bicarbonate ion results in a decrease in the ratio of bicarbonate ion to carbon dioxide in the extra cell fluid

metabolic acidosis

5

what is respiratory alkalosis due to a decrease in carbon dioxide concentration caused by hyperventilation compensated by

renal excretion of bicarbonate ion

6

where does primary active hydrogen secretion involving a hydrogen-transporting ATPase occur

late distal tubule in intercalated cells

7

where does most bicarbonate reabsorption occur

proximal tubule

8

where is volatile acid excreted from

lungs

9

where is nonvolatile acids excreted form

kidneys

10

what are some major systems regulated H+ concentration

chemical acid-base buffer systems of the body fluids
respiratory center
kidneys

11

define buffer

substance that can reversibly bind H+

12

what does addition of a strong acid lead to in the bicarbonate buffer system

formation of a weak acid

13

what does addition of a strong base to the bicarbonate buffer system lead to

formation of weak base

14

what excretes the increases levels of HCO30 in the bicarbonate buffer system

kidneys

15

what do decreased CO2 levels in the bicarbonate buffer system do to respiration rate

decreases it

16

what is bicarbonate concentration regulated primarily by in the bicarbonate buffer system

kidneys

17

what is the pCO2 controlled by in the bicarbonate buffer system

rate of respiration

18

what is the most important extracellular buffer system

bicarbonate buffer system

19

what do metabolic acid base disorders primarily result form

change in bicarbonate concentrations in extracellular fluid

20

what does respiratory acid base disorders primarily result from

change in pCO2

21

why is phosphate buffer system important

plays major role in buffering tubular fluid and intracellular fluids

22

why is the phosphate buffer system important in the kidneys (2 reasons)

usually becomes greatly concentrated in the tubules
lower pH of the tubular fluid brings the operating range of the buffer closer to the pk of the buffer system

23

what is the primary method for removing nonvolatile acids

through renal excretion

24

what are mechanisms for regulating extracellular H+

kidneys reabsorb filtered extracellular H+
kidneys can secrete hydrogen ions
kidneys produce new bicarbonate ions

25

where does hydrogen ion secretion via secondary transport occur

almost all parts of the tubules except descending and ascending thin limbs of the loop of henle

26

where does bring active hydrogen secretion begin

in the late distal tubules in intercalated cells and involves a hydrogen-transporting ATPase

27

where does the majority of bicarbonate reabsorption occur

proximal tubule

28

why is carbonic anhydrase necessary

it is necessary for the formation of carbonic acid from carbon dioxide and water

29

how is incomplete titration used to correct acidosis

in metabolic acidosis, new bicarbonate ion is added to the extracellular fluid

30

how is incomplete titration used to correct alkalosis

in metabolic alkalosis, bicarbonate ions are removed form the extracellular fluid by renal excretion

31

how does the tubular epithelium secretion hydrogen ion

via primary active transport

32

what is active transport resulting in hydrogen ion secretion carried out by

intercalated cells

33

how does hydrogen ion secretion in the proximal tubule occur

via secondary sodium-hydrogen counter-transport

34

where are the sodium-hydrogen exchanges located

on the apical (luminal) membranes of the renal epithelial cells

35

where are sodium-potassium-ATPase exchangers found

basal membranes

36

what is the lower limit of pH that can be achieved in normal cells

4.5

37

how are nonvolatile acids primarily removed

via renal excretion

38

what is the minimal urine pH

4.5

39

how are excess hydrogen ions eliminated

through binding with phosphate or ammonia ions

40

how do the kidneys correct alkalosis

failing to reabsorb all the filtered bicarbonate ions or adding hydrogen ion to the extracellular fluid

41

what happens when there is a decreases in the ration of bicarbonate ion to carbon dioxide in extracellular fluid

decrease in bicarbonate ion: metabolic acidosis
increase in CO2: respiratory acidosis

42

what is the primarily compensatory response to respiratory acidosis

increase in plasma bicarbonate ion due to addition of new bicarbonate by the kidney

43

what is the primary compensatory response to metabolic acidosis

increase in ventilation rate

44

what is the renal compensation to metabolic acidosis

adds new bicarbonate ion to extracellular fluid

45

in alkalosis, how is excess bicarbonate excreted

in urine

46

what is respiratory alkalosis caused by

hyperventilation

47

what is the compensatory response to respiratory alkalosis

reduction in plasma bicarbonate ion concentration caused by renal excretion of bicarbonate ion

48

what is metabolic alkalosis caused by

rise in the extracellular fluid bicarbonate ion concentration

49

what is the compensatory response to metabolic alkalosis

decreased ventilation
increased renal bicarbonate ion excretion