There is conservation of mass
Fick principle states that?
In steady state, cardiac output of left and right ventricles is equal
Fundamental assumption of Fick principle's application in measurement of cardiac output
In stead state, rate of O2 consumption by body must equal amount of O2 leaving lungs in pulmonary vein minus amount of O2 returning to lungs in pulmonary artery
Fick principle's application in measurement of cardiac output is?
Oxygen consumption = amount of oxygen leaving lungs in pulmonary vein - amount of oxygen returning to lungs in pulmonary artery
Calculation for oxygen consumption
Pulmonary blood flow × oxygen content of pulmonary venous blood
Calculation for amount of oxygen in pulmonary veins
Pulmonary blood flow × oxygen content of pulmonary arterial blood
Calculation for amount of oxygen in pulmonary artery
The assumption is that pulmonary blood flow = cardiac output of right heart = cardiac output of left heart
Why is pulmonary blood flow the same?
Cardiac output × [O2 ]pulmonary vein − Cardiac output × [O2 ]pulmonary artery
Calculation for oxygen consumption in terms of cardiac output
Calculation for cardiac output using oxygen consumption
Unit for cardiac output
Unit for oxygen consumption
mL O2/mL blood
Unit for [O2]pulmonary vein and [O2]pulmonary artery
Total oxygen consumption of body in a 70kg man
By sampling blood from a peripheral artery (because none of the O2 added to blood in lungs has been consumed by the tissues yet)
How to measure oxygen content of pulmonary venous blood?
Can be sampled either in pulmonary artery itself or in right ventricle
How to measure oxygen content of pulmonary arterial blood?
Fick principle can be applied to measurement of blood flow to ____
Renal blood flow can be measured by dividing O2 consumption of kidneys by difference in O2 content of renal arterial blood and renal venous blood
Example of calculating renal blood flow by using Fick principle