acid-base balance Flashcards
increase of H+ causes
decrease in pH
glucose metabolism –>
lactic acid
fatty acid metabolism –>
ketone body acids
protein metabolism –>
strong acids
normal extracellular H+ concentration
40 nm
normal extracellular H+ concentration determines the function of
enzymes
channels
receptors
production of H+ in the body
CO2 + H2O <-> H2CO3 <-> HCO3-
regulation of pH
buffers (seconds)
respiratory system (minutes)
renal system (days)
buffers
minimize change in pH
phosphate buffer
HPO4^2- + H <–> H2PO4-
protein buffer
Hb
Hb + H+ <–> HbH+
HCO3-/CO2 system
open system
add or remove:
- HCO3- kidney
- CO2 - respiration
respiratory system regulation
high H+ –> increase ventilation –> decrease CO2 –> H+
renal system regulation
excrete H+ or reabsorb or create HCO3-
creation of new HCO3- in renal system
glutamine is broken down into HCO3- and NH4+
- NH4+ excreted in urine
- HCO3- goes into blood
excretion of acid
H+ secreted in exchange for Na+
H+ binds to phosphate buffer and is excreted
acidosis (increased H+)
high CO2 - respiratory
low HCO3- : metabolic
alkalosis (decreased H+)
low CO2 : respiratory
high HCO3- : metabolic
respiratory acidosis
always associated with high CO2
cause of respiratory acidosis
decreased ventilation, severe asthma
compensation for respiratory acidosis
kidneys secrete more H+ and reabsorb more HCO3-
respiratory alkalosis is always associated with low
CO2
cause of respiratory alkalosis
increased ventilation - high altitude
compensation for respiratory alkalosis
kidneys secrete less H+ and reabsorb less HCO3-
metabolic acidosis is always associated with
low HCO3-
- due to loss of HCO3 or addition of H+
cause of metabolic acidosis
kidney failure - dont reabsorb HCO3-
diarrhea - loss of HCO3- from intestines
exercise - production of lactic acid
compensation for metabolic acidosis
respiratory system
increased ventilation - decreased CO2 - decreased H+
metabolic alkalosis is always associated with
high HCO3-
- due to addition of HCO3- or loss of H+
cause of metabolic alkalosis
abuse of antacids (HCO3-)
vomiting - loss of H+ from the stomach
metabolic alkalosis compensation
respiratory system
decreased ventilation - increased CO2 - increased H+
