Acid-Base Flashcards
what is the significance of glutamine in ammonia buffering
glutamine has two ammonia groups that it breaks down and releases in the tubular fluid
how does decrease in PaCO2 affect H+ secretion
decreases H+ secretion
how does an increase in angiotensin II affect H+ secretion
increases H+ secretion
renal compensation for respiratory alkalosis
decrease bicarbonate and decrease acid excretion in the urine
pH range of intracellular fluid
6.0-7.4
what change in pH is needed to double or half the hydrogen concentration
0.3
how does increase in plasma HCO3 affect H+ secretion
decreases H+ secretion
what happens to the hydrogen concentration in the ICF in acidemia
increases (takes in H+)
what happens to the hydrogen concentration in the ICF in alkalemia
decreases (donates H+)
how does a decrease in ECF volume affect H+ secretion
increases H+ secretion
what are the two ways ammonia can cross the apical membrane
through an ammonia/Na+ transporter
passively
renal compensation for respiratory acidosis
increase bicarbonate and increase acid excretion in the urine
how does an increase in ECF volume affect H+ secretion
decreases H+ secretion
how does decrease in plasma HCO3 affect H+ secretion
increases H+ secretion
how does hypokalemia affect H+ secretion
increases H+ secretion
causes of respiratory alkalosis
hypoxia
anxiety (hyperventilation)
progesterone
aspirin poisoning
ventilators
high altitude
pH of venous blood and interstitial fluid
7.35
how does increase in filtered load of HCO3- affect H+ secretion
increases H+ secretion
how does hyperkalemia affect H+ secretion
decreases H+ secretion
why is ammonium not a titratable acid
because of the high pK of NH4+ means that no H+ is removed from NH4+ during titration to a pH of 7.4
main causes of high anion gap metabolic acidosis
DKA
ethanol
lactic acidosis
opiates
aspirin
main causes of non-anion gap metabolic acidosis
diarrhea
spironolactone
post-hypocapnia
how does bicarbonate help carry Na+ out of the cell and into the blood in the proximal tubule
through the HCO3-/Na+ symporter - passively diffuses to promote Na+ transport
3 ways in which CO2 is transported
7% dissolved
23% w/ hemoglobin
70% as bicarbonate
respiratory and renal compensation for metabolic alkalosis
hypoventilation, or longer breaths
decrease bicarbonate regeneration and decrease acid excretion in urine
pH of arterial blood
7.40
main causes of metabolic alkalosis
vomiting
licorice
post-hypercapnia
diuretics
hyperaldosteronism
loop or thiazide diuretics
what is net acid excretion made of
1/3: titratable acids (primarily phosphate and salts with a pka < 7.4)
2/3: NH4+
where is bicarbonate reabsorbed
85% PCT 10% TAL 4.9% CT 0.1% urine
respiratory and renal compensation for metabolic acidosis
hyperventilation
increase bicarbonate regeneration and increase acid excretion in the urine
how does increase in PaCO2 affect H+ secretion
increases H+ secretion
