Exam 3: 25 Mar Pulmonary Function Tests and Blood Gas Physiology Flashcards
What are pulmonary function tests used for?
To assess lung function and generate flow-volume loops
They capture data that can be plotted in various ways for interpretation.
What is the solubility coefficient of oxygen in blood?
0.003 ml of O2 per mmHg PO2
This means that for every mmHg of partial pressure of oxygen, 0.003 ml can dissolve in blood.
How much oxygen does hemoglobin carry per gram?
1.34 ml of O2 per gram
This indicates the capacity of hemoglobin to transport oxygen in the blood.
What is the normal arterial oxygen content in blood?
20.1 ml/dL
This value represents the amount of oxygen carried in the arterial blood.
How does fetal hemoglobin differ from adult hemoglobin?
Fetal hemoglobin has a higher affinity for oxygen
This allows fetuses to extract oxygen from maternal blood more efficiently.
What form of carbon dioxide is primarily transported in blood?
Bicarbonate (90%)
CO2 is also transported in dissolved and carbamino forms.
What is the typical oxygen saturation of venous blood?
70-75%
This is lower than arterial blood saturation.
What is the impact of pH on the oxygen-hemoglobin dissociation curve?
Changes in pH affect hemoglobin’s affinity for oxygen
A lower pH (more acidic) decreases affinity, shifting the curve to the right.
What is the solubility coefficient of carbon dioxide in blood?
0.06 ml of CO2 per mmHg
This indicates how much CO2 can dissolve in blood based on its partial pressure.
What is the relationship between hemoglobin oxygenation and CO2 transport?
Deoxygenated blood carries more CO2
This is due to the Bohr effect, where increased CO2 enhances oxygen release.
How do temperature changes affect oxygen binding to hemoglobin?
Higher temperatures decrease oxygen binding affinity
This makes it more difficult for hemoglobin to hold onto oxygen.
What is the calculation for determining dissolved oxygen in blood?
PO2 (mmHg) x solubility coefficient
The solubility coefficient for oxygen is 0.003 ml/mmHg.
What is the role of carbonic anhydrase in CO2 transport?
Facilitates conversion of CO2 to bicarbonate
This reaction helps maintain acid-base balance in the blood.
What happens to hemoglobin saturation at low hemoglobin levels?
It decreases the total oxygen content
For example, at 10% saturation, only 2 ml of O2 can be carried.
Fill in the blank: The dissolved oxygen in blood cannot meet the metabolic demand of __________ ml O2 each minute.
250
This illustrates the importance of hemoglobin in oxygen transport.
True or False: Venous blood has a higher oxygen saturation than arterial blood.
False
Arterial blood has a higher oxygen saturation than venous blood.
What are the three forms of carbon dioxide in blood?
- Dissolved
- Carbamino
- Bicarbonate
These forms play a crucial role in CO2 transport and acid-base balance.
What does 100% saturation of hemoglobin indicate?
All binding spots on hemoglobin are occupied by oxygen
If hemoglobin is at 10% saturation with 15 grams of hemoglobin, how much oxygen is bound?
2 mL of O2
What two factors are needed to determine how much oxygen is bound to hemoglobin?
- Carrying capacity of hemoglobin
- Hemoglobin oxygen saturation percentage
What is the normal hemoglobin level in a healthy adult?
15 grams
What is the structural composition of adult hemoglobin?
- 2 alpha subunits
- 2 beta subunits
What type of hemoglobin is found in fetuses?
Fetal hemoglobin
What is the difference in subunit composition between fetal hemoglobin and adult hemoglobin?
- Fetal hemoglobin has gamma subunits instead of beta subunits