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Question

Blood that is 100% saturated with oxygen carries 105 cm^3 of oxygen in 1 dm^3 (litre) of blood.

Calculate the volume of oxygen released from 1 dm^3 of blood when that has become 90% saturated.

Now This is how i didn the question

100% ---> 105
90% ----> x

x= 90 x 105/100%

x= 94.5 dm^3

this may be wrong... Any suggestions into solving this problem would be very helpful. I have search in 4 texted books btw and no luck.

Answer 1

Your working is correct but you may have fallen for the teacher's trap! The question asked how much has been released - now the question is not really clear but it seems to assume that the blood which was 100% has now released (105-94.5=) 10.5 cc of oxygen to now become 90% saturated.

Answer 2

The O2 content of blood = Hg conc x O2 carrying capacity of Hg x % saturation + dissolved amount (pO2 x solubility). 105 ml/L is 100% sat. 90% saturated blood = 94.5 ml/L. The dissociation curve in not linear but you can approximate it as linear. Without knowing Hemoglobin concentration and pO2, I couldn't give you a more precise answer.

Answer 3

O2 delivery for the pherifery = cardiac out put *oxygen content
for 100%saturation the out put is 1005ml/min
for 90 %saturation 904.5ml/min

Answer 4

i think your answer is correct.

1000 - - - 100
x -- ---90 x=900

1000 --> 105
900 ---> x

X = 94.5