Physiology 8 Flashcards
normal range of HCO3?
23-27mmol/l
normal pH range?
7.35-7.45
normal arterial pCO2?
35-45mmHg
if normal acid base balance is disrupted what needs to be restored first
pH
what substances act as buffers in acid base disturbances?
HCO3
CO2
Hb
____ blood has a greater affinity for H+ ions
unoxygenated
what organ regulates and controls bicarbonate?
kidneys
causes of respiratory acidosis?
COPD
airway restriction eg tumour
chest injury
respiratory depression eg general anaesthesia
CO2 is __ in respiratory acidosis
retained
there is hypoventilation in respiratory acidosis T or F
T
where does CO2 retention drive equilibrium?
right
what will resp acidosis present with:
pH
CO2
HCO3
low ph
inc co2
normal HCO3
there is alot of extracellular buffering in respiratory acidosis T or F
F, virtually none for respiratory disorders
why is H+ secreted by the kidney in respiratory acidosis?
the excess CO2 stimulates release
how is respiratory acidosis fixed?
treat the cause
need to get respiration back to normal
how is pH brought back to normal in respiratory compensation?
kidneys make H+ to bind to the bicarbonate ions to be excreted as ammonium in the urine
there is hypoventilation in respiratory alkalosis T or F
F, hyper
there is __ CO2 in respiratory alkalosis
low
causes of respiratory alkalosis?
altitute
hyperventilation
anxiety
co2 removal drives equilibrium to the….
left
effect of respiratory alkalosis on:
pH
CO2
bicarb
ph high
co2 low
bicarb normal
H+ secretion is high in respiratory alkalosis T or F
F, co2 is low so it cant stimulate the kidneys to secrete H+
how do you fix respiratory alkalosis?
restore normal ventilation
remove hco3 in urine
causes of metabolic acidosis?
ingestion of acid
DKA (excessive production of H+)
lactic acidosis
excessive loss of bicarb eg diarrhoea
there is excess __ in metabolic acidosis?
H+ (NOT from CO2)
why is HCO3 low in metabolic acidosis?
trying to buffer the excess H+
effect of metabolic acidosis on:
pH
HCO3
CO2
ph low
CO2 normal
HCO3 high
how is pH restored in metabolic acidosis?
respiratory system helps by causing hyperventilation (Removes co2 so moves equilibrium to the left to get rid of H+)
what is the equilibrium equation for acids and bases?
CO2 + H20 H2CO3 H + HCO3
the urine in metabolic acidosis is acidic/basic?
acidic
is metabolic acidosis or alkalosis more common?
acidosis
effect of metabolic alkalosis on:
pH
CO2
HCO3
high pH
normal CO2
high HCO3
cause of metabolic acidosis?
vomiting
ingestion of alkali
aldosterone hypersecretion
there is a loss of __ and/or and gain of ___ in metabolic acidosis
loss of H+
gain of HCO3
what does the resp system do to restore a metabolic alkalosis?
slows ventilation down so that CO2 is retained (shifts equilibrium to the right so more H+ is gained)
