Pulmonary Gas Exchange

Question 1

what calculation will give you the partial pressure of a gas at sea level?

Answer 1

multiplying the percent of the gas times 670 mmHm

Question 2

Henry’s law

Answer 2

the total gas that dissolves in a fluid is directly proportional to the partial pressure of that gas at equilibrium

Question 3

Dalton’s law

Answer 3

total pressure exerted by nonreactive gases = sum of the partial pressure of individual gases

Question 4

Boyle’s Law

Answer 4

volume = 1/pressure, for ideal gases at constant temperature

Question 5

adding water vapor to the alveolus does what

Answer 5

decreases the partial pressures of all the other gases in the mixture

Question 6

alveolar pressure = ___ at the end of a normal quiet ____

Answer 6

0 mmHg inspiration cycle

Question 7

a normal Va/Q ratio = ___

Answer 7

.8

Question 8

when Va = 0, Va/Q =

Answer 8

0, but there is still perfusion, this is due to airway obstruction (mucous plug). the blood gas composition remains unchanged

Question 9

Va/Q = infinity when Q =

Answer 9

0, but there is still ventilation (no gas exchange): this is due to vascular obstruction

Question 10

what would the ratio of Va/Q equal if there was an airway obstruction and ventilation 0 but Q still have a value?

Answer 10

0 when there is still profusion

Question 11

what would the Va/Q ration equal if there was a blockage of profusion (meaning Q = 0) ?

Answer 11

infinity

Question 12

How does the alveolar gas composition change when there is no blood flow to the alveolus?

Answer 12

a physiological shunt occurs, but the alveolar gas remains unchanged because no contact is made with the blood