Gas Transport Flashcards
What are the two forms of O2 in the blood?
dissolved and associated with hemoglobin
The amtoun of dissolved O2 in the blood is proportional to what?
the partial pressure of O2
0.0003 ml/mmHg/dL
What will be the amount of O2 associated with hemoglobin at the 40 mmHg O2 of venous blood?
about 15 ml/dl
What is maximal O2 binding to hemoglobin?
1.39 ml/g
What is O2 saturation?
the amount of O2 combined with hemogllbin divided by the maximal O2 capacity of hemoglobin
Normal O2 sat is over what for arterial blood? venous vlood?
over 95% for arterial blood and over 75% for venous blood
What will shift the O2 dissociation curve to the RIGHT?
Anything that makes you need a higher pO2 for binding - it means there’s less affinity for O2
- decreased pH
- increased CO2
- increased temperature
- increased diphosphoglycerate
(anything that happens during exercise)
Does carbon monozide have a greater or lower affinity for hemoglobin than O2?
greater - 240 times greater
How do you treat carbon monoxide poisoning?
1
What are the three forms that CO2 is carried in the blood?
- dissolved CO2
- Bicarbonate
- carbamino compounds
How much CO2 is carried in dissolved form?
10%
What’s the predominant way CO2 is carried?
bicarb
How does bicarb move in regards to the RBC? What ion is affected?
bicarb can diffuse out of the RBC (unlike H+) and it’s exchanged for chloride (chloride shift)
Why is deoxygenated hemoglobin a better carrier for CO2?
deoxygenated hemoglobin has more H+ in it = more acidic
What percentage of CO2 is carried bound to Hb?
only 5% (more if O2 is low)
What shape is the O2 dissociation curve and what shape is the CO2 dissociation curve?
THe O2 dissociation curve is sigmoidal while the CO2 dissociation curve is more linear
Since the CO2 dissociation curve is much mor elinear and steeper than that of O2, what does this mean for the amount of CO2 that can be carried in the blood?
the blood can carry more CO2 than O2
Bicarb concentration is largely controlled by what organ?
kidneys
pCO2 is largely controlled by what organ?
lungs
Respiratory acidosis is caused by what in general?
CO2 retention from ypoventilation or ventilation-perfusion mismatch
Respiratory alkalosis is caused by what in general?
excessive exhalation of CO2 in hyperventilation or exposure to high altitude
Once the hemoglobin gets to the capillaries in skeletal muscle, why does the O2 move into the tissue?
because the pO2 in muscle is very low - like 1-3 mmHg
What molecule helps to keep the pO2 int he muscle uniform?
myoglobin
In summary, how much O2 is transported in dissolved form in 1 dL the blood
.3 ml/Dl
