V/Q Flashcards
In a normal upright individual, describe Ventillation and perfusion in the apices.
What would be the normal VQ Ratio for this area.
It receives moderate amount of ventilation and little blood flow.
Means ratio can be higher than 0.8.
In a normal upright individual, describe Ventillation and perfusion in the lower regions of the lung.
What would be the normal VQ Ratio for this area.
Ventillation is moderately increased while the blood flow is greatly increased.
Results on ratio being less than 0.8
So what is the general trend of the V/Q ratio from apices to bases?
It generally decreases
What is the normal overall V/Q ratio?
How is the value derived?
4:5 or 0.8
It is an average from the V/Q ratios from the apices to the bases.
What is the respiratory exchange ratio?
Quantity of O2 and CO2 exchanged in a period of 1 minute.
What is external respiration?
Gas exchange between pulmonary capillaries and alveoli.
What is the respiratory quotient (RQ)?
Ratio between volume of O2 consumed and volume of CO2.
Formula: RQ=VCO2/VO2
Which is normally 0.8
What is the normal amount of PAo2 that is in the pulmonary vein before it enters the heart?
100 mmHg
What is the normal amount of PACo2 that is in the pulmonary vein before it enters the heart?
40 mmHg
What part of the lung has the highest pH value?
The apices
Which part of the lung has the lowest pH?
The bases
How much oxygen is normally consumed by body tissues in 1 minute?
250 mL of O2
How much CO2 is produced by the tissue in 1 minute?
200 mL
What pulmonary disorders increase V/Q ratios?
5 examples
Pulmonary embolism
Partial or complete obstruction in pulmonary arteries
(wasted ventilation or Dead space Ventillation)
Destruction of pulmonary vessels
Decreased cardiac output
Pulmonary disorders that decrease V/Q ratios
3 examples
Obstructive lung disorders
Restrictive lung disorders
Hypoventilation
