Blood Transport of Gases Flashcards
what is most oxygen in blood reversibly bound to
hemoglobin
what percentage of oxygen in blood is bound to hemoglobin
> 97%
what happens to the oxygen that is not bound to hemoglobin
it circulates dissolved in blood
what is henry’s law
amount of gas dissolved is directly proportional to partial pressure of that gas
is O2 soluble in aqueous solution
solubility is very low
how much O2 is dissolved in blood at a usual arterial pressure
3ml of O2 per L of blood
how much O2 does blood leaving the lungs contain
~200mL O2 per L, 197ml/l is bound to hemoglobin
how much O2 does a 25kg greyhound consume at rest
125 mL O2 per min
how much O2 does a 25kg greyhound consume during a race
4500 ml O2 per min
what would be the necessary cardiac output if O2 was only carried as dissolved in blood
1500 L of blood
what does a hemoglobin contain
4 heme groups each with 1 iron atom that can bind 1 O2 molecule
how many molecule of O2 does 1 hemoglobin bind
4
what is oxygen saturation
the amount of oxygen carried divided by the total oxygen capacity of blood
what is % saturation
amount O2 bound / max capacity of Hb for O2
when is saturation at 100%
when all 4 site of all the blood Hb are bound
when is the saturation 50%
when half the potential binding sites are occupied
what kind of law does the binding of O2 to Hb follow
a mass action law
what is pO2 responsible for
the amount of O2 dissolved in blood
what happens to the blood in lung capillaries
dissolved O2 increases = more HbO2
what happens when blood passes through tissue capillaries
dissolved O2 decreases = dissociation of HbO2 occurs
what shape does the oxygen saturation curve follow
sigmoid shape based on equilibrium
under normal conditions, what is the percentage saturation in blood leaving lung
100%
under normal conditions, what is the percentage saturation in blood out of tissue
75%
how much oxygen is used at rest
only 25% of carrying capacity
what is the main factor fir saturation
Hb concentration since Hb is completely saturated in the lungs
how much oxygen does 1g Hb carry
1.34ml of O2
what is the normal concentration of saturation
150g/L -> 200 ml O2
what causes anemia
o2 transport is reduced proportionally to amount of Hb
what compensates for the decrease of pO2 in air in high altitude
compensates by increasing the number of erythrocytes and Hb
what are factors affecting Hb saturation
pH
temp
2,3DPG
what are the 3 forms that carry CO2 in blood
the physical solution
carbamino compounds (bound to proteins)
bicarbonate
what percentage of CO2 is carried in physical solution (dissolved in blood)
5-10%
how much more soluble is CO2 in water compared to O2
20x more soluble in water than O2
what does CO2 bind to on proteins
-NH groups (especially hemoglobin)
what percentage of CO2 binds to proteins/carbamino acids
15-20%
what does CO2 have a strong affinity for in terms of proteins and why
deoxyhemoglobin b/c no O2
what percentage of CO2 is carried by bicarbonate
70-75%
where does bicarbonate and CO2 react
in erythrocytes
what is the formula for bicarbonate
HCO3-
what happens to bicarbonate in plasma
is diffuses and is much more soluble than CO2
what happens with bicarbonate and CO2 in lungs
the opposite reaction forms and it is converted back to CO2
