lect 25- Blood gas transport Flashcards
what occurs due to the increase (3x) of diffusing capacity of oxygen during exercise
increase surface area of capillaries participating in diffusion
more nearly idea Va/Q ratio in the upper parts of lungs
what factors determine PO2
rate of oxygenate transport to tissues
rate of oxygen consumption by tissues
what is the mean normal intracellular PO2
23 mm Hg
what is the normal arterial blood entering tissues and venous blood leaving tissues PCO2
arterial: 40 mm Hg
venous: 45 mm Hg
what does a decrease in blood flow from normal do to peripheral tissue CO2
increases it
how much O2 can 1 gram Hb bind to
1.34 ml O2
what happens to oxygen-hemoglobin when PO2 is high (pulm capillaries)
oxygen binds with hemoglobin
what happens to oxygen-hemoglobin when PO2 is low (tissue capillaries)
oxygen is released from hemoglobin
what shifts the oxygen-hemoglobin curve to the right
decreased pH increased H+ increased CO2 increased temperature increased BPG
what happens when cellular pO2 is more than 1 mm Hg
[ADP] becomes the limiting factor in the rates of chemical reactions
what are the 3 ways carbon dioxide is transported
small amount dissolved in blood
most is transported at carbonic acid
remainder is transported as carbamino hemoglobin
define bohr effect
increase in blood CO2 causes oxygen to be displaced from hemoglobin (shifts oxygen-hemoglobin dissociation curve to right)
define haldane effect
binding of oxygen with hemoglobin displaces CO2 from blood, causing hemoglobin to become a stronger acid (which is less likely to bind with CO2)
what happens when hemoglobin because increasingly acidic
it releases H+ ions
why is blood bright red in carbon monoxide poisoning
oxygen content of blood is reduced but PO2 of blood may be normal
