lect 25- Blood gas transport Flashcards Preview

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Flashcards in lect 25- Blood gas transport Deck (15):

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