Acid Base Balance Flashcards
what is hypercarbia
- excess CO2
CO2 transport intimately related to precise regulation of
- plasma, cellular, tissue pH
acids other than those based on CO2 are termed
- metabolic acids
what compounds constitute the primary buffer system that regulates pH
what controls these
- HCO3- (kidneys)
- CO2 (lungs)
what is critical for regulation of pH
- ratio of bicarb/CO2
how is HCO3- exported to plasma
- by the chloride shift
what blood pH value defines acidosis
- below 7.35
what blood pH value defines alkalosis
- above 7.45
do acids and conjugate bases or conjugate acids and bases of weak acid/base neutralize each other
- no
definition of an acid
- donates protons
definition of a base
- accepts protons
definition of strong acid/base
- dissociate completely in aqueous solutions
when acid or base is added to a buffer
why?
- the solution resists pH changes
- added H+ or OH- can be neutralized by base or acid in buffer
what happens to pH when CO2 elimination = CO2 production
- pH is constant
If CO2 is eliminated faster than it is produced, what will happen to the blood
- blood will become alkalotic
if more CO2 is produced than is eliminated, what will happen to the blood
- blood will become acidotic
respiratory acids are eliminated by
- lung
metabolic acids are eliminated by
- the kidney
metabolic, non-volatile, fixed acids are
- end products of protein, amino acid, lipid, and nucleic acid metabolism.
the effectiveness of a buffer is determined by
- its concentration pKa
- ambient pH
buffering power is greater in what kind of system
- an open system
- why bicarb buffering with CO2 regulation by lung ventilation is so effective
regulation of PCO2 and HCO3-
- regulated independently
how does the cellular cytosol act as a buffer
- uses a combination of phosphate and protein buffers
how does Hb act as a buffer
- it is rich in histidine
time frame of cellular buffering
importance of this
- transient
- gives the body time to react and compensate
an importance part of physiologic buffering is moving _______ between plasma and cells
- acids and bases
all volatile acids and bases are buffered how
why
- intracellularly
- role of carbonic anhydrase inside cells
respiratory acidosis due to
result
due to which condition
- insufficient excretion of CO2 by the lungs
- PaCO2 rises, pH falls
- hypoventilation
respiratory alkalosis due to
result
due to which condition
- excess excretion of CO2 by the lungs
- PaCO2 falls and plasma pH rises
- hyperventilation
role of secreted HPO4 and NH3 into tubule lumen (toward urine)
- bind H+ and lose more acid in the urine
metabolic acidosis due to
what does CO2 do
result
due to which condition
- metabolic acids that consume HCO3-
- CO2 stays normal
- becomes more acidic
- hypoxia, exercise, diabetes, diarrhea
metabolic alkalosis due to
what does CO2 do
result
due to which condition
- loss of metabolic acids that increase plasma HCO3-
- CO2 normal
- becomes more alkalotic
- excess emesis, diuretics
compensation for respiratory acidosis
- kidney increases secretion of H+ in urine and retains HCO3- in plasma
compensation for respiratory alkalosis
- kidney decreases secretion of H+ and decreases retention of HCO3-
time of response from renal
- renal response takes 6-12 hours
compensation for metabolic acidosis
- ventilation increases to decrease CO2 to normalize pH
what is Kussmaul breathing
- rapid shallow breathing that can progress to deep labored breathing in severe diabetic kept acidosis
compensation for metabolic alkalosis
- body decreases ventilation to increase CO2
what is the normal range of anion gap
- 3-16
what does anion gap and electro-neutrality mean
which are more
how is that compensated for
- equal numbers of positive and negative charges
- more cations than anions
- made up by negative charges on proteins and minor organic phosphates
what will acid or base insults do?
- consume or generate HCO3-
what happens to the ion gap in DKA
- anions acetoacetate and beta-hydroxybutyrate increase which creates high anion gap
plasma pH is sensed by chemoreceptors where
- in the brain
response of brain chemoreceptors to acidosis
- excites them to increase ventilation
response of brain chemoreceptors to alkalosis
- quiets them to decrease ventilation
time frame for respiratory compensation
- very rapid, minutes
