L24: Blood Gas Exchange Flashcards
upper limit of infinite blood flow =
95
limited by max po2 in arterial blood
normal pCO2 inter/intracell
intra = 46 extra = 45
arterial blood entering = 40
venous blood leaving = 45
in exercise you may require up to ____ oxygen
20x
during exercise Va/Q becomes more ____ in the ___ lungs
more ideal
upper lungs
what factors determine tissue pO2
- rate of o2 transport to tissue
2. rate of o2 consumption by the tissue
decrease in blood flow or metabolic rate from normal will ______ peripheral tissue CO2
increase
6x increase in blood flow will _____ peripheral CO2 to almost equal ?
decrease
that in arterial blood
o2 saturation in venous blood vs. arterial
75% venous
97% arterial
oxygen bound to heme groups in arterial vs venous blood
venous 3/4 of oxygen bound
arterial - most o2 is bound
what is the oxygen utilization coefficient
25%
75 - 85% in strenuous exercise
___ oxygens per hemoglobin
4
when po2 is high in pulmonary capillaries, oxygen binds w/ _____ . when po2 is low, oxygen is ?
hemoglobin
released from hemoglobin
effect of intracell ADP
when cell po2 is more than 1
ADP becomes limiting factor in the rates of chemical rxns
between normal venous and arterial blood __ mL of oxygen is transported to tissues. and in exercise ?
5 ml
15 in exercise
increased pCO2 = ______ pH
decreased
and o2 is forced from the hemoglobin
what factors shift the oxygen hemoglobin dissociation curve to the right
- increased H+ ions
- increased CO2
- increased temp
- increased BPG
a shift in the O2-Hb curve to the right = ____ pH
lower pH
how does increase in blood co2 and H+ ions effect the o2-hb curve?
shift to right
whereas a decrease in these will shift it left
what are the 3 ways that co2 can be transported in the blood
- 7% dissolved in the blood
- 70% transported as carbonic acid
- remaining transported as carbamino hemoglobin
requirments for co2 to be transported as carbonic acid
requires carbonic anhydrase
employs bicarbonate/chloride transporter
bohr effect
increase in blood co2 causes o2 to be displaced from hemoglobin
shifts curve to right
Haldane effect
binding of o2 w/ hemoglobin displaces co2 from blood
shifts curve to right
why is it so dangerous to breath carbon monoxide
because Hb has a higher affinity for it than o2
binds 250x stronger than o2
why is blood bright red in CO poisoning
o2 content of blood is greatly reduced but po2 of blood may be normal thus blood is bright red
