renal 7 - acid base Flashcards
when is arterial plasma pH acidosis
when its under 7.35
when is arterial plasma pH alkylosis
when its above 7.45
what is the pH for normal ACF
between 7.35 and 7.45
which pH are fatal
under 6.8 above 7.8
what is an acid in terms of H+
releases H+ in solution
what is an base in terms of H+
accepts H+ in solution
what is a volatile acid
CO2
what is a non volatile acid
organic and inorganic acids from other sources than CO2
what does metabolism of sulfur containing amino acids produce
sulfuric acid, a non volatile acid
what does metabolism of lysine, arginine and histidine produce
hydrochloric acid
what is a buffer
any substance that binds to H+
what is a buffer composed of
a weak acid and its conjugate base
what is the buffer in the extracellular system
CO2 HCO3-
what are the intracellular buffers
phosphate ions and proteins
what are the intracellular buffers
hemoglobin
which organs are responsible for balancing [H+]
kidneys and lungs
what does carbonic anhydrase do
turn CO2 +H2O into H2CO3-
what causes the generation of H+ from H2 CO3-
passage of blood through peripheral tissues
do lungs regulate H+ long term or short term
short term
what causes respiratpry inbalances
hyper/oventilation, resp. malfunction
what does high [H+] do to ventilation
stimulates
what does low [H+] do to ventilation
inhibits
do kidneys regulate H+ long term or short term
long term
what do kidneys do to help alkalosis
kidneys excrete more bicarbinate
what do kidneys do to help acidosis
kidneys synthesize new bicarbonate and send it into blood
what is the reabsorption of HCO30 dependent on
H+ secretion
is most of HCO3- reabsorbed or secreted normally
reabsorbed
is reabsorption of HCO3- active or passive
active
where does reabsorption of HCO3- happen
proximal tubule, ascending loop of Henle, cortical collecting duct
why isnt there H+ in urine
because bicarbonate that was filtered in the lumen combines with H+ then CO2 gets reabsorbed
what is the transport mechanism of H+
depends on the part of the tubule segment
how does the body respond to acidosis (mechanism 1)
addition of HCO3- in plasma by binding the H+ to HPO4- (net gain of HCO3- in plasma)
how does the body respond to acidosis (mechanism 2)
uptake of glutamine from filtrate or peritubular plasma which forms NH4+ and HCO3- causes active secretion of NH4+ (counter Na/NH4 pump) and the reabsorption of HCO3- in plasma
where does the addition of HCO3- to plasma via glutamine happen
in proximal tubule only
what happens to glutamine metabolism in alkalosis
decerase
what happens to ammonium excretion in alkalosis
decrease
what causes respiratory acidosis (2 things)
- decreased ventilation
- increased blood PCO2
how does kidney respond to respiratory acidosis
kidneys compensate by secreting H+ (either bound to HPO4 2- or excrete NH4+ from glutamine)
what disease can cause respiratory acidosis
emphysema
what causes respiratory alkalosis (2 things)
hyperventilation, decreased blood PCO2
what environment can cause respiratory alkalosis
high altitude
how does kidney respond to respiratory alkalosis
excreting HCO3- in urine
can the kidney excrete acidic or basic urine
ya both
when can metabolic acidosis happen (2 illness, 1 other)
diarrhea (loss of bicarbonate), diabetes mellitus (cant reabsorb what has been filtered), severe exercise (anaerobic, lactic acid production)
what does metabolic acidosis result in
increased ventilation and increased H+ secretion
what does metabolic alkalosis result in
decreased ventilation and increased HCO3- excretion
what illness can cause metabolic alkalosis
prolonged vomiting
