PULMONARY PHYSIOLOGY 2 QUESTIONS AND ANSWERS
What is the composition of air? - CORRECT ANSWER✅✅Air is composed of a mixture of gases; each of
the gases contributes its partial pressure to the total pressure of the air
What is Dalton's Law? - CORRECT ANSWER✅✅The total pressure of a mixture of gases is equal to the
sum of the partial pressures of each of the constituent gases
What is atmospheric pressure at sea level? - CORRECT ANSWER✅✅760 mmHg
What is the percentage of gases in air? - CORRECT ANSWER✅✅N2 = 78%; O2 = 21%; CO2 = 0.03%
What are the partial pressures of gases at sea level? - CORRECT ANSWER✅✅PN2 = 593 mmHg; PO2 =
159 mmHg; PCO2 = 0.3 mmHg
What is the sum of partial pressures at sea level? - CORRECT ANSWER✅✅PN2 + PO2 + PCO2 = 760
mmHg
What is alveolar air? - CORRECT ANSWER✅✅Humidified, exchanges gases with blood, mixes with
residual air
What are the partial pressures in alveolar air? - CORRECT ANSWER✅✅PN2 = 569 mmHg; PO2 = 104
mmHg; PCO2 = 40 mmHg
What determines the rate of diffusion of gases? - CORRECT ANSWER✅✅Partial pressures and solubility
of gas determine the rate of diffusion of each gas and gas exchange between the blood and alveolus
What is gas exchange? - CORRECT ANSWER✅✅Gas exchange occurs between the alveolar air and the
pulmonary capillaries
What is the result of gas exchange in lungs? - CORRECT ANSWER✅✅Increased oxygen concentration
and decreased carbon dioxide concentration in blood leaving the lungs and entering systemic arteries
, What is alveolar gas exchange? - CORRECT ANSWER✅✅O2 is transported from alveoli to blood (oxygen
loading) and CO2 from blood enters alveoli (carbon dioxide unloading) and is exhaled out
What happens after oxygenation in lungs? - CORRECT ANSWER✅✅Oxygenated blood enters left atrium
and from left ventricle is carried by systemic arteries to peripheral tissue
What is systemic gas exchange? - CORRECT ANSWER✅✅O2 is transported from blood to tissues
(oxygen unloading) and CO2 is transported from tissues to blood (carbon dioxide loading)
What happens to deoxygenated blood? - CORRECT ANSWER✅✅Carried by systemic veins and vena
cavae to right atrium and from right ventricle carried by pulmonary arteries to lungs
What drives gas exchange in alveoli? - CORRECT ANSWER✅✅Partial pressure gradient of gases
What is the air-water interface? - CORRECT ANSWER✅✅There is an air-water interface where gas
exchange occurs between air in alveoli and blood in capillaries
How do gases diffuse at the air-water interface? - CORRECT ANSWER✅✅Gases diffuse down their
concentration gradient from higher partial pressure to lower partial pressure
What determines diffusion at the interface? - CORRECT ANSWER✅✅Partial pressures and solubility
determine the rate of diffusion
What drives movement of gases? - CORRECT ANSWER✅✅Concentration gradient of gases
Example of O2 gradient - CORRECT ANSWER✅✅PO2 = 104 mmHg in alveolar air vs 40 mmHg in blood
Example of CO2 gradient - CORRECT ANSWER✅✅PCO2 = 46 mmHg in blood vs 40 mmHg in alveolar air
What is the composition of air? - CORRECT ANSWER✅✅Air is composed of a mixture of gases; each of
the gases contributes its partial pressure to the total pressure of the air
What is Dalton's Law? - CORRECT ANSWER✅✅The total pressure of a mixture of gases is equal to the
sum of the partial pressures of each of the constituent gases
What is atmospheric pressure at sea level? - CORRECT ANSWER✅✅760 mmHg
What is the percentage of gases in air? - CORRECT ANSWER✅✅N2 = 78%; O2 = 21%; CO2 = 0.03%
What are the partial pressures of gases at sea level? - CORRECT ANSWER✅✅PN2 = 593 mmHg; PO2 =
159 mmHg; PCO2 = 0.3 mmHg
What is the sum of partial pressures at sea level? - CORRECT ANSWER✅✅PN2 + PO2 + PCO2 = 760
mmHg
What is alveolar air? - CORRECT ANSWER✅✅Humidified, exchanges gases with blood, mixes with
residual air
What are the partial pressures in alveolar air? - CORRECT ANSWER✅✅PN2 = 569 mmHg; PO2 = 104
mmHg; PCO2 = 40 mmHg
What determines the rate of diffusion of gases? - CORRECT ANSWER✅✅Partial pressures and solubility
of gas determine the rate of diffusion of each gas and gas exchange between the blood and alveolus
What is gas exchange? - CORRECT ANSWER✅✅Gas exchange occurs between the alveolar air and the
pulmonary capillaries
What is the result of gas exchange in lungs? - CORRECT ANSWER✅✅Increased oxygen concentration
and decreased carbon dioxide concentration in blood leaving the lungs and entering systemic arteries
, What is alveolar gas exchange? - CORRECT ANSWER✅✅O2 is transported from alveoli to blood (oxygen
loading) and CO2 from blood enters alveoli (carbon dioxide unloading) and is exhaled out
What happens after oxygenation in lungs? - CORRECT ANSWER✅✅Oxygenated blood enters left atrium
and from left ventricle is carried by systemic arteries to peripheral tissue
What is systemic gas exchange? - CORRECT ANSWER✅✅O2 is transported from blood to tissues
(oxygen unloading) and CO2 is transported from tissues to blood (carbon dioxide loading)
What happens to deoxygenated blood? - CORRECT ANSWER✅✅Carried by systemic veins and vena
cavae to right atrium and from right ventricle carried by pulmonary arteries to lungs
What drives gas exchange in alveoli? - CORRECT ANSWER✅✅Partial pressure gradient of gases
What is the air-water interface? - CORRECT ANSWER✅✅There is an air-water interface where gas
exchange occurs between air in alveoli and blood in capillaries
How do gases diffuse at the air-water interface? - CORRECT ANSWER✅✅Gases diffuse down their
concentration gradient from higher partial pressure to lower partial pressure
What determines diffusion at the interface? - CORRECT ANSWER✅✅Partial pressures and solubility
determine the rate of diffusion
What drives movement of gases? - CORRECT ANSWER✅✅Concentration gradient of gases
Example of O2 gradient - CORRECT ANSWER✅✅PO2 = 104 mmHg in alveolar air vs 40 mmHg in blood
Example of CO2 gradient - CORRECT ANSWER✅✅PCO2 = 46 mmHg in blood vs 40 mmHg in alveolar air
