Heart output

[victor]

Hey, does anyone can help me to count heart output if from the question we know the pressure of pulmonary veins and pulmonary arthery? just give me the formula please...
I really shocked that this kind of question appeared in my 1st grade of senior high school 2 years ago....even my teacher can't explained it...

[b_d_41501]

Cardiac Output = 2ml x Pulse Pressure x Heart Rate

[victor]

well, this is the question:
Heart beat : 70 beats per minute
Pulmonary vein consists of : 0.24 ml O2/ml
Pulmonary arthery consists of : 0.16 ml O2/ml
O2 consumption for the body : 500 ml per minute
How many is the heart output?
a. 1.65 L/minute
b. 4.55 L/minute
c. 5.00 L/minute
d. 6.25 L/minute
e. 8.00 L/minute
This is the question from my exam when I'm still at the first grade of senior high school. Because this can be considered into homework, please just give me the formula..thanks

[b_d_41501]

OHHH, Ok, i gotcha now. lol. Ignore the Heart Beat, it's irrelevant. Here's the equation:

V02=Q(Ca-Cv)
V02= Volume of O2 consumed
Q = Cardiac Output
Ca = Arterial volume of O2 per mL of Blood
Cv = Veinous volume of O2 per mL of Blood

Simply solve for Q and convert the mL to L. I did it and got D. Work it yourself and see what you get.

[victor]

Hey...thanks man..you've solved my 2-year pended question...
By the way...you'd gotten D for that? it's better than me..I?got nothing..even a Z letter

[b_d_41501]

No problem, victor. Human Biology is my specialty since i'm gonna be a Dr. If you have anymore like that, just post'em and i'll help out.

[victor]

Hey, I've count it and got a little bit problem. You said that the equation is:
VO2=Q(Ca-Cv) and I'll input the number
500 = Q (0.24 - 0.16)
500 = Q (0.
Q=625 mL/minute.
If we change it into L/minute it will become 0.625 L/minute. Am I wrong. Please apologize since I really cannot do math..

[b_d_41501]

That is true., hmm.......maybe the choices on the original test were typed wrong, because this is the equation.

[MrMistery]

Actually i calculated it now and it is correct.
If you do 0.24-0.16 you get 0.08 ml of oxygen that is consumed by the body in one journey of the blood from the pulmonary vein to the pulmonary artery(actually the big circulation). So your body consumes 0.08 ml of oxygen for every ml of blood. Since we know it consumes 500 ml os oxygen in one minute, we simply divide 500 by 0.08 and get 6250 ml of blood that is needed for that 500 ml of oxygen. Turning this into litres you get 6.25L/minute, so the correct answer is indeed d.
I am sorry i didn't do it before but it seemed b_d_41501 had done it

[b_d_41501]

I realize now the error of my calculation. Thanks Mystery.

[victor]

Hey, I've just realized it...thanks Andrew..