Acid-Base Physiology Revisited

Question 1

what is electroneutrality?

Answer 1

sum of positive ions = sum of negative ions

Question 2

what is chemical neutrality?

Answer 2

[H+]=[OH-]

Question 3

do we exist in chemical neutrality?

Answer 3

no
alkaline

Question 4

what are the strong ions in mammalian biological fluids?

Answer 4

Na+
Cl-
K+
SO4
lactate or keto acids

Question 5

what is the strong ion difference (SID)?

Answer 5

sum of all strong cation concentrations minus the sum of all strong anion concentrations

Question 6

what is the strong ion difference normally in plasma?

Answer 6

+42 mEq/L

Question 7

what does it mean that the strong ion difference in negative?

Answer 7

strong anions exceed strong cations
solution is acidic

Question 8

any change in strong ion difference must change both [H+] and [OH-]; therefore ____________________ is an independent variable, while ___________________ are dependent variables

Answer 8

strong ion difference
[H+] and [OH-]

Question 9

_________ is a new independent variable, and [H+] and [P-] are dependent variables that change when _________ changes

Answer 9

[Ptot]
[Ptot]

Question 10

is bicarbonate a dependent or independent variable?

Answer 10

dependent: changes when independent variables are manipulated

Question 11

what are the independent variables?

Answer 11

water dissociation constant (does not change)
strong ion difference
[Ptot]
PCO2

Question 12

from where do acid base derangements arise?

Answer 12

abnormalities of strong ion difference, proteins, and PCO2

Question 13

where are therapeutic efforts to correct acid base derangements directed?

Answer 13

correction of strong ion difference and PCO2

Question 14

what does PCO2 depend on?

Answer 14

respiration
changes occur rapidly

Question 15

what does the concentration of strong ions depend on?

Answer 15

gastrointestinal absorption and gastrointestinal and renal loss (normal and pathologic)
changes occur over hours

Question 16

what does an increased strong ion difference cause?

Answer 16

metabolic alkalosis

Question 17

what are the major weak acids in plasma?

Answer 17

proteins

Question 18

what does hyperproteinemia cause?

Answer 18

metabolic acidosis

Question 19

a decrease in total protein in a patient would result in _____________

Answer 19

metabolic alkalosis

Question 20

how does the kidney lower [H+]?

Answer 20

excretes more [Cl-] than [Na+]
raises strong ion difference

Question 21

does movement of bicarbonate in or out of plasma or renal tubules alter [H+]?

Answer 21

no
both are dependent variables

Question 22

why do you give sodium chloride to a patient with metabolic alkalosis?

Answer 22

in metabolic alkalosis: SID increased
sodium chloride: SID 0
will decrease SID in plasma