Acid-base 1 Flashcards
1
Q
normal blood pH
A
7.4
2
Q
what is formula for pH
A
-log[H]
3
Q
what is typical buffer
A
weak acid and its conjugate base
4
Q
3 keys to a good buffer
A
- need high [c] available
- need to be able to restore buffer when used
- pK ph buffer should be near pH of body fluid
5
Q
what is pK
A
pH at which [HA] = [A-]
6
Q
bronstead lowry def of acid base
A
acid is H donor and base is H acceptor
7
Q
what is blood buffer system
A
H+ + HCO3- <> H2CO3 <> H2O + CO2
8
Q
normal blood levels
A
H+ = 40 HCO3 = 24 CO2 = 40
9
Q
why does CO2 not increase when HCO3 binds with H to buffer
A
blow off excess respiratorily
10
Q
where is more HCO3 coming from
A
kidneys
11
Q
where does most H+ come from
A
diet (esp protein breakdown)
12
Q
2 renal responses to acidosis
A
- reabsorb
2. regenerate - via NH4+ production and secretion
13
Q
where is HCO3- reabsorbed
A
PCT
14
Q
how is HCO3- reabsorbed
A
- luminar NHE3 exchanger pulls NA in off NaHCO3
- Na crossing drives H+ into tubule
- H+ reacts with HCO3- which makes CO2
- CO2 goes into blood
- leftover HCO3- goes into blood
15
Q
4 aspects that determine HCO3- reabsorb
A
- filtered HCO3 load - less reabsorb
- luminal [H] - more reab
- ICF [H] - more
- avidity for Na reabsorb - more
