70 Questions
What is the driving force that causes the flow of O2 during gas diffusion?
Pressure
Which factor is considered the least important in gas diffusion according to the text?
Molecular weight
What equation can be used to calculate the permeability (K) for gas diffusion?
K = A/dx * Solubility/√MW
What does DLCO stand for in the context of gas diffusion?
Diffusion Capacity of the Lung for CO
Why is the solubility of CO2 set at 20 and CO at 0.8 in the context of gas diffusion?
Due to higher solubility than O2
How can the diffusion capacity for oxygen (DLO2) be calculated if DLCO is given as 17 ml/min/mmHg?
(DLCO * 20) / 0.8
What happens to the extraction ratio in the described patient compared to normal?
It increases to 50%.
If a muscle is paralyzed, what happens to the PO2 in the interstitial?
It increases to 100mmHg.
What effect does giving a vasodilator have on the PO2 in the interstitial?
It remains the same at 100mmHg.
In a normal muscle with higher metabolism, what happens to the PO2 in the interstitial?
It decreases.
What happens to ABGs during exercise according to the text?
They stay the same.
In comparison of a normal lung and a damaged lung, what does it mean if the DLO2 is lower than normal?
The oxygen diffusion is compromised in damaged lungs.
During exercise, why does the entire lung become zone 3?
Due to the distension of the capillaries and improvement in V/Q.
What makes DLO2 around 63 during exercise?
The lung working about 3 times more efficiently.
In a patient with CO poisoning, why may their oxygen concentration be very small despite normal ABG results?
Because CO binds 250 times more tightly to hemoglobin than O2.
Why won't neurons in the brain alert a patient with CO poisoning despite low oxygen concentration?
Because the ABG results for oxygen are normal.
How does anemia (7.5g/dl hemoglobin) affect oxygen concentration despite normal ABG and O2 saturation?
Causes a decrease in the normal concentration of O2.
What can be concluded about hemoglobin levels causing a decrease in oxygen concentration?
Normal hemoglobin levels are crucial for maintaining oxygen concentration.
What is the name of the ratio that describes the relationship between the volume of carbon dioxide produced and the volume of oxygen consumed during respiration?
Respiratory exchange ratio
If proteins have a respiratory exchange ratio of 0.8, what does this ratio signify?
More oxygen is consumed than carbon dioxide produced
When the diffusion capacity is 1/8 of its original value due to thickening of the lung membrane, what happens to the arterial partial pressure of oxygen (PO2)?
Decreases significantly
Considering a venous admixture in the heart, why might there be a difference between the expected normal arterial blood gas value for oxygen (100) and the actual value (95)?
Mixing of venous blood with arterial blood
If half of all red blood cells are removed from a sample with an arterial PO2 of 100 mmHg and an oxygen content of 20 ml O2/dl, what will happen to the arterial PO2?
It will increase to 30 mmHg
If the systemic arterial PO2 is 100 mmHg and the hematocrit is 40%, what will be the systemic arterial PO2 if blood is added to increase hematocrit to 50%?
70 mmHg
What is the driving force for the flow of O2 during gas diffusion?
Difference in pressure
What can be used to calculate the permeability (K) for gas diffusion?
(A/dx) * (Sol/√MW)
What is considered the least important factor in gas diffusion according to the text?
Molecular weight
Why is the solubility of CO set at 20 and CO2 at 0.8 in the context of gas diffusion?
To reflect their different solubilities compared to O2
What does the DLCO stand for in the context of gas diffusion?
Diffusion Capacity of the Lung for CO
If DLCO is 17 ml/min/mmHg, what would be the calculated DLO2 if CO2 solubility was used instead of Sol/√MW?
-3.4 ml/min/mmHg
If a muscle is paralyzed, what effect does it have on the partial pressure of oxygen (PO2) in the interstitial?
It increases
What happens to the extraction ratio in the described patient compared to normal?
It increases dramatically
During exercise, what occurs with the partial pressure of oxygen (PO2) in the lungs?
It remains stable
Why does the partial pressure of oxygen (PO2) not change in the interstitial when a vasodilator is administered?
Flow increase compensates for PO2 decrease
In a normal muscle with higher metabolism, what happens to the partial pressure of oxygen (PO2) in the interstitial?
It decreases
What happens to arterial blood gas (ABGs) during exercise?
ABGs remain unaffected
What is the reason behind CO being used as a measurement in DLCO2 instead of O2?
CO binds 250 times tighter than O2 to hemoglobin
Why might a patient with CO poisoning have normal ABG results for oxygen despite low oxygen concentration?
Neurons in the brain do not sense low oxygen due to normal ABG
What happens to the oxygen saturation when a patient has 7.5g/dl of hemoglobin in blood?
Remains normal despite lower hemoglobin levels
What does it mean when the entire lung becomes zone 3 during exercise?
Three times more efficient due to capillary distension
How does CO poisoning affect the oxygen concentration in the blood despite normal ABG for oxygen?
Decreases it by half
What is the consequence of a patient having 1/2 of normal hemoglobin concentration on the oxygen concentration in the blood?
Halves the oxygen concentration
If the arterial partial pressure of oxygen (PO2) is 100 mmHg and the hematocrit is 40%, what will be the arterial PO2 if half of the red blood cells are removed?
PO2=30 mmHg
If systemic arterial PO2 is 100 mmHg and hematocrit is 40%, what would be the systemic arterial PO2 if blood is diluted to decrease the hematocrit to 30%?
PO2=60 mmHg
Considering the respiratory exchange ratio, which type of food consumption would result in the highest VCO2/VO2 ratio?
Glucose
If the oxygen consumption by cells increases due to higher energy demands, what would be the impact on the arterial partial pressure of oxygen (PO2)?
PO2 will decrease
How does an increase in cardiac output affect the arterial partial pressure of oxygen (PO2)?
No effect on PO2
What impact does thickening of the lung membrane have on the diffusing capacity for oxygen (DLCO) and arterial partial pressure of oxygen (PO2)?
DLCO and PO2 both decrease
What is the driving force behind the flow of O2 during gas diffusion?
Pressure difference
Which factor is inversely proportional to resistance in the context of gas diffusion?
Surface area
What factor can be considered the least important in gas diffusion based on the provided text?
Molecular weight
How can the permeability (K) for gas diffusion be calculated based on the provided equation?
(Thickness * Solubility) / Surface Area
Given the DLCO (diffusion capacity of the lung for CO) as 17 ml/min/mmHg, what would be the calculated DLO2 if CO's solubility is used instead of Sol/√MW?
4.25 ml/min/mmHg
What causes the entire lung to become zone 3 during exercise?
Distension of capillaries
Why might a patient with CO poisoning not be alerted by the neurons in the brain despite low oxygen concentration in the body?
Normal ABG values for O2
What is the main problem faced by a patient with CO poisoning despite having normal ABG results for oxygen?
Low oxygen concentration in blood
What would be the oxygen concentration in the blood of a patient with 7.5g/dl hemoglobin (anemic) compared to a person with normal hemoglobin levels?
Half of normal concentration
What happens to the V/Q ratio when the entire lung becomes zone 3 during exercise?
Increases
What happens to the partial pressure of oxygen (PO2) in the interstitial when a muscle is normal but has higher metabolism?
It decreases
During exercise, what happens to the partial pressure of oxygen (PO2) in the lungs?
It remains the same
What is the impact on the partial pressure of oxygen (PO2) in the interstitial when a vasodilator is administered?
It remains the same
If a muscle is paralyzed, what effect does it have on the partial pressure of oxygen (PO2) in the interstitial?
It increases
What happens to arterial blood gas (ABGs) during exercise?
They remain unchanged
How does giving a vasodilator affect the flow of oxygen in the interstitial space?
It has no effect on the flow of oxygen
What would be the systemic arterial PO2 if the blood is diluted to decrease the hematocrit to 30% from an initial value of 100 mmHg at 40% hematocrit?
PO2=60 mmHg
If the arterial PO2 is 100 mmHg and the oxygen content is 20ml O2/dl, what will be the arterial PO2 if all red blood cells are removed?
PO2=0 mmHg
What happens to the extraction ratio in a patient with CO poisoning compared to a normal individual?
Increases
If DLCO is given as 17 ml/min/mmHg, what would be the calculated DLO2 if CO solubility was used instead of O2 solubility?
$240.6 , ml/min/mmHg$
In a normal muscle with higher metabolism, what happens to the arterial partial pressure of oxygen (PO2) compared to the interstitial PO2?
Arterial PO2 increases compared to interstitial PO2
What can be concluded about hemoglobin levels causing a decrease in oxygen concentration despite normal ABG and O2 saturation?
Low hemoglobin levels lead to a decrease in oxygen concentration
Learn about the transport of gases in biological systems, including the concepts of resistance, permeability, and diffusion. Understand how to calculate permeability using the given equation and explore the factors that influence the flow of gases.
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